doc/gutshtml/SessionOn2.html - view

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Thu Apr 7 06:56:20 2005 UTC (19 years, 1 month ago) by albertel
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CVS tags: version_2_9_X, version_2_9_99_0, version_2_9_1, version_2_9_0, version_2_8_X, version_2_8_99_1, version_2_8_99_0, version_2_8_2, version_2_8_1, version_2_8_0, version_2_7_X, version_2_7_99_1, version_2_7_99_0, version_2_7_1, version_2_7_0, version_2_6_X, version_2_6_99_1, version_2_6_99_0, version_2_6_3, version_2_6_2, version_2_6_1, version_2_6_0, version_2_5_X, version_2_5_99_1, version_2_5_99_0, version_2_5_2, version_2_5_1, version_2_5_0, version_2_4_X, version_2_4_99_0, version_2_4_2, version_2_4_1, version_2_4_0, version_2_3_X, version_2_3_99_0, version_2_3_2, version_2_3_1, version_2_3_0, version_2_2_X, version_2_2_99_1, version_2_2_99_0, version_2_2_2, version_2_2_1, version_2_2_0, version_2_1_X, version_2_1_99_3, version_2_1_99_2, version_2_1_99_1, version_2_1_99_0, version_2_1_3, version_2_1_2, version_2_1_1, version_2_1_0, version_2_12_X, version_2_11_X, version_2_11_4_uiuc, version_2_11_4_msu, version_2_11_4, version_2_11_3_uiuc, version_2_11_3_msu, version_2_11_3, version_2_11_2_uiuc, version_2_11_2_msu, version_2_11_2_educog, version_2_11_2, version_2_11_1, version_2_11_0_RC3, version_2_11_0_RC2, version_2_11_0_RC1, version_2_11_0, version_2_10_X, version_2_10_1, version_2_10_0_RC2, version_2_10_0_RC1, version_2_10_0, version_2_0_X, version_2_0_99_1, version_2_0_2, version_2_0_1, version_2_0_0, version_1_99_3, version_1_99_2, version_1_99_1_tmcc, version_1_99_1, version_1_99_0_tmcc, version_1_99_0, loncapaMITrelate_1, language_hyphenation_merge, language_hyphenation, bz6209-base, bz6209, HEAD, GCI_3, GCI_2, GCI_1, BZ4492-merge, BZ4492-feature_horizontal_radioresponse, BZ4492-feature_Support_horizontal_radioresponse, BZ4492-Support_horizontal_radioresponse

- ENV -> env

1: <html> 2: 3: <head> 4: 5: <meta name=Title 6: 7: content="Session One: Problem Engine/Special Targets (grade, edit, print) (Guy)"> 8: 9: <meta http-equiv=Content-Type content="text/html; charset=macintosh"> 10: 11: <link rel=Edit-Time-Data href="Session%20On2_files/editdata.mso"> 12: 13: <title>Session One: Problem Engine/Special Targets (grade, edit, print) (Guy)</title> 14: 15: <style> 44: 45: </style> 46: 47: </head> 48: 49: <body bgcolor=#FFFFFF link=blue vlink=purple class="Normal" lang=EN-US> 50: 51: <div class=Section1> 52: 53: <h2>Session One: Problem Engine/Special Targets (grade, edit, print) (Guy)</h2> 54: 55: <h3><a name="_Toc421867127">Tags</a></h3> 56: 57: <ul type=disc> 58: 59: <li>Response tags </li> 60: 61: </ul> 62: 63: Arguments for all response tags 64: 65: <ul type=disc> 66: 67: <ul type=circle> 68: 69: <li>ID, if this isn't set it will be set during the publication step. 72: 73: It is used to assign parameters names in a way that can be tracked if 74: 75: an instructor modifies things by hand. </li> 76: 77: <li>name optional, if set, it will be used by the resource 80: 81: assembly tool when one is modifying parameters. </li> 82: 83: </ul> 84: 85: </ul> 86: 87: Implemented response tags 88: 89: <ul type=disc> 90: 91: <ul type=circle> 92: 93: <li><responseparam> if it appears it should be inside of a <*response> 96: 97: tag, defines an externally adjustable parameter for this question. Arguments: 98: 99: </li> 100: 101: <ul type=square> 102: 103: <li>default required, specifies a default value for the 106: 107: parameter </li> 108: 109: <li>name required, specifies an internal name for the 112: 113: parameter </li> 114: 115: <li>type required specifies the type of parameter, one 118: 119: of "tolerance", "int", "float", "string", 120: 121: "date" (configuration of paramters is handled by lonparmset.pm 122: 123: and parameter.html) </li> 124: 125: <li>description a string describing the parameter, this is what 128: 129: is used to talk about a parameter outside of a problem </li> 130: 131: </ul> 132: 133: <li><parameter> exactly the same as <responseparam> currently, 136: 137: but should not appear inside of a <*response> </li> 138: 139: <li><numericalresponse> implements a numerical answer, it needs an internal 142: 143: <textline> for the 144: 145: response to go in. It checks all styles of numerical supported in CAPA. 146: 147: Possible args are: </li> 148: 149: <ul type=square> 150: 151: <li>answer required, specifies the correct answer, may 154: 155: be either a perl list or scalar</li> 156: 157: <li>units optional, specifies unit of correct answer, 160: 161: CAPA style</li> 162: 163: </ul> 164: 165: <li><stringresponse> implements a string answer, it needs an internal 168: 169: <textline> for the 170: 171: response to go in. It can check the string for either case or order. </li> 172: 173: <ul type=square> 174: 175: <li>answer required, specifies the correct answer, may 178: 179: be either a perl list or scalar</li> 180: 181: <li>type optional, CAPA style str args, cs/ci/mc </li> 184: 185: <ul type=square> 186: 187: <li>cs - case senesitive, order important</li> 188: 189: <li>ci - case insenesitive, order important</li> 190: 191: <li>mc - case insenesitive, order unimportant</li> 192: 193: </ul> 194: 195: </ul> 196: 197: <li><essayresponse> implements a ungraded large text response, it 200: 201: need an internal <textarea> for the response to go in. </li> 204: 205: <li><imageresponse> implements a image click style image submission, 208: 209: uses the foil structure tags <a href="#foil">below</a>. Additional tags 210: 211: that should appear in a <foil> are: </li> 212: 213: <ul type=square> 214: 215: <li><image> required, the contained text specifies a published 218: 219: graphical resource that is the image used, should only appear once per 220: 221: foil</li> 222: 223: <li><rectangle> required, the contained text specifies a rectangular 226: 227: area that is correct, should look like (1,2)-(3,4), at least 1 required</li> 228: 229: <li><text> required, the contained text is printed on 232: 233: top of the image.</li> 234: 235: </ul> 236: 237: <li><optionresponse> implements a "select from these choices" 240: 241: style question, the choices are specified by the instructor, it uses the 242: 243: foil structure tags <a href="#foil">below</a> with this additional args: 244: 245: </li> 246: 247: <ul type=square> 248: 249: <li><foilgroup> is required to have options which 252: 253: should be a perl list of possible options for the student. </li> 254: 255: </ul> 256: 257: <li><radiobuttonresponse> implements a true / false style question with 260: 261: 1 correct answer.it uses the foil structure tags <a href="#foil">below</a> 262: 263: but the value of a <foil>can only be "true" 264: 265: or "false" or "unused" </li> 266: 267: <li><dataresponse> implements a straight data storage entry idea, 270: 271: needs and interveing input tag like <textline> to work correctly. 272: 273: Arguments: </li> 274: 275: <ul type=square> 276: 277: <li>name internal name for the value, it will have the 280: 281: part id and respose id added on to it </li> 282: 283: <li>type type of data stored in this response field, 286: 287: should be one of the types supported by parameter.html </li> 288: 289: <li>display a string that will be used to describe the field 292: 293: when interfacing with humans </li> 294: 295: </ul> 296: 297: </ul> 298: 299: </ul> 300: 301: o      304: 305: <externalresponse> implements the ability to have an external program grade a response, 308: 309: expects either a <textline> or <textfield> inside the tag. 310: 311: Arguments: 312: 313: <ul type=disc> 314: 315: <ul type=circle> 316: 317: <ul type=square> 318: 319: <li>url the url to submit the answer and form to, does 322: 323: not need to be a LON-CAPA machine. </li> 324: 325: <li>answer a string or scalar variable that can encode 328: 329: something that should encode the correct answer, in some cases this 330: 331: may be nothing. </li> 332: 333: <li>form a hash variable name that will be submitted 336: 337: to the remote site as a HTTP form. </li> 338: 339: </ul> 340: 341: </ul> 342: 343: </ul> 344: 345: The response of the remote server needs to be in XML as follows. 346: 347: <pre> <loncapagrade>     <awardetail> CORRECT     </awardetail>     <message> A message to be shown to the students     </message> </loncapagrade>            </pre> 348: 349: <ul type=disc> 350: 351: <ul type=circle> 352: 353: <ul type=square> 354: 355: <li><loncapagrade> no arguments but must surround the response. 358: 359: </li> 360: 361: <li><awardetail> required inner tag, the response inside must 364: 365: be one of the detailed responses that appears in the data storage documentation 366: 367: (CVS:loncapa/doce/homework/datastorage) </li> 368: 369: <li><message> optional message to have shown to the student 372: 373: </li> 374: 375: </ul> 376: 377: </ul> 378: 379: </ul> 380: 381: <ul type=disc> 382: 383: <li><a name=foil>Foil Structure Tags</a> </li> 384: 385: </ul> 386: 387: All tags that implement a foil structure have an optional arg of max 388: 389: that controls the maximum number of total foils to show. 390: 391: <ul type=disc> 392: 393: <ul type=circle> 394: 395: <li><foilgroup> required, must be the tag that surrounds all 398: 399: foil definitions </li> 400: 401: <li><foil> required, all data inside is a possible foil 404: 405: </li> 406: 407: <li><conceptgroup> optional, surrounds a collection of <foil>, 410: 411: when a problem is displayed only one of the contained <foil>is selected 412: 413: for display. It receives one required argument concept. 414: 415: </li> 416: 417: </ul> 418: 419: <li>Hint structure </li> 420: 421: </ul> 422: 423: All of these tags must appear inside a <*response> tag. 426: 427: <ul type=disc> 428: 429: <ul type=circle> 430: 431: <li><hintgroup> Tag that surrounds all of a hint. </li> 434: 435: <li><hintpart> required, Tag to implement conditional hints. 438: 439: It has a required argument on. When a <*hint> tag 440: 441: named the same as the value the on attribute evaluates to be correct the 442: 443: <hintpart> will show. If no other <hintpart> are to show then 444: 445: all hintparts with a on of "default" 446: 447: will show </li> 448: 449: <li><numericalhint> has all the arguments that <numericalresponse>, 452: 453: does and the required attribute name which should be set 454: 455: to the value of which <hintpart> will be shown. </li> 456: 457: </ul> 458: 459: <li>Input Tags </li> 460: 461: </ul> 462: 463: This group of tags implement a mechanism for getting data for students, they 464: 465: will usually be used by a <*response>. 466: 467: <ul type=disc> 468: 469: <ul type=circle> 470: 471: <li><textarea> creates a Large text input box, If data appears 474: 475: between the start and end tags, the data will appear i the textarea if 476: 477: the student has not yet made a submission. Additionally it takes two arguments 478: 479: rows and cols which control the height and width of the area 482: 483: respectively. It defaults to 10 and 80. </li> 484: 485: <li><textline> creates a single line of input element, it accepts 488: 489: 1 argument size which controls the width on the textline, 490: 491: it defaults to 20. </li> 492: 493: </ul> 494: 495: <li>Output Tags </li> 496: 497: </ul> 498: 499: This group of tags generate useful pieces of output. 500: 501: <ul type=disc> 502: 503: <ul type=circle> 504: 505: <li><standalone> everything in between the start and end tag 508: 509: is shown only on the web, and only if the resource is not part of a course. 510: 511: </li> 512: 513: <li><displayduedate> this will insert the current duedate if one 516: 517: is set into the document. It is generated to be inside a table of 1x1 518: 519: elements </li> 520: 521: <li><displaytitle> this will insert the title of the problem from 524: 525: the metadata of the problem </li> 526: 527: <li><window> the text in between is put in a popup javascript 530: 531: window </li> 532: 533: <li><m> the inside text is LaTeX, and is converted to 536: 537: HTML (or MathML) on the fly, if the argument eval is set 538: 539: to "on" the intervening text will have a perl var expansion 540: 541: done to it before being converted. </li> 542: 543: <li><randomlabel> shows a specified image with images or text 546: 547: labels randomly assigned to a set of specific locations, those locations 548: 549: may also have values assigned to them. There is a hash generated conating 550: 551: the mapping of labels to locations, labels to values, and locations to 552: 553: values. Example: </li> 554: 555: </ul> 556: 557: </ul> 558: 559: <pre>  <randomlabel bgimg="URL" width="12" height="45" texwidth="50">     <labelgroup name="GroupOne" type="image">       <location x="123" y="456" value="10" />       <location x="321" y="654" value="20" />       <location x="213" y="546" value="13" />       <label description="TEXT-1">IMG-URL</label>       <label description="TEXT-2">IMG-URL</label>       <label description="TEXT-3">IMG-URL</label>     </labelgroup>     <labelgroup name="GroupTwo" type="text">       <location x="12" y="45" />       <location x="32" y="65" />       <location x="21" y="54" />       <label>TEXT-1</label>       <label>TEXT-2</label>       <label>TEXT-3</label>     </labelgroup>    </randomlabel>         </pre> 560: 561: Arguments: 562: 563: <ul type=disc> 564: 565: <ul type=circle> 566: 567: <ul type=square> 568: 569: <li>bgimg either a fully qualified URL for an external 572: 573: image, or a loncapa resource, it supports relative references (../images/apicture.gif), 574: 575: the image must either be a GIF or JPEG </li> 576: 577: <li>width the width of the image in pixels </li> 580: 581: <li>height the height of the image in pixels </li> 584: 585: <li>texwidth the width of the image in millimeters </li> 588: 589: </ul> 590: 591: </ul> 592: 593: </ul> 594: 595: Internal tags: 596: 597: <ul type=disc> 598: 599: <ul type=circle> 600: 601: <ul type=square> 602: 603: <li><labelgroup> 1 required, multiple allowed. Declares a group 606: 607: of locations and labels associated with them. 608: 609: Arguments: </li> 610: 611: <ul type=square> 612: 613: <li>name this is the name of the group, a hash with 616: 617: this name will be generated holding the mappings for later use in 618: 619: the problem. For each location a value will be set for which label 620: 621: is there, (EX. $hash{'1'}="TEXT-2"). For locations with 622: 623: values the hash will contain 2 items, a location to value mapping 624: 625: ($hash{'value_1'}=10), and a label to value mapping ($hash{'labelvalue_2'}=10). 626: 627: For all image style of labels there will also be a label description 628: 629: to label URL mapping ($hash{'image_2'}=IMG-URL). Also the entry 'numlocations 630: 631: will be set to the total number of locations that exist. (Note that 632: 633: locations and labels start counting from 1.) </li> 634: 635: <li>type the type of labels in this group, either 'image' 638: 639: or 'text' </li> 640: 641: </ul> 642: 643: <li><location> declares a location on the image that a label 646: 647: should appear at 648: 649: Arguments: </li> 650: 651: <ul type=square> 652: 653: <li>x the x value of the location in pixels </li> 656: 657: <li>y the y value of the location in pixels </li> 660: 661: <li>value a scalar value to associate at this location 664: 665: (optional) </li> 666: 667: </ul> 668: 669: <li><label> declaration of a label, if this is a text type 672: 673: labelgroup the internal text should be the text of the label (HTML is 674: 675: not currently supported), if this is an image type of label the internal 676: 677: text must be a LON-CAPA resource specification, and the description 678: 679: filed must be set. 680: 681: Arguments: </li> 682: 683: <ul type=square> 684: 685: <li>description a required field for image labels, it will 688: 689: be used when setting values in the hash. </li> 690: 691: </ul> 692: 693: </ul> 694: 695: </ul> 696: 697: <li>Scripting </li> 698: 699: </ul> 700: 701: These tags allow the document to behave programatically 702: 703: <ul type=disc> 704: 705: <ul type=circle> 706: 707: <li><display> the intervening perl script is evaluated in 710: 711: the safe space and the return value of the script replaces the entire 712: 713: tag </li> 714: 715: <li><import> causes the parse to read in the file named in 718: 719: the body of the tag and parse it as if the entire text of the file had 720: 721: existed at location of the tag </li> 722: 723: <li><parserlib> the enclosed filename contains definitions for 726: 727: new tags </li> 728: 729: <li><script> if the argument type is set to 732: 733: "loncapa/perl" the enclosed data is a perl script which is evaluated 734: 735: inside the perl Safe space. The return value of the script is ignored. 736: 737: </li> 738: 739: <li><scriptlib> the enclosed filename contains perl code to 742: 743: run in the safe space </li> 744: 745: <li><block> has a required argument condition 748: 749: that is evaluated, it the condition is true everything inside the tag 750: 751: is evaluated, if it is false everything inside the block tag is skipped 752: 753: </li> 754: 755: <li><notsolved> everything inside the tag is skipped if the 758: 759: problem is "solved" </li> 760: 761: <li><postanswerdate> everything inside the tag is skipped if the 764: 765: problem is before the answer date </li> 766: 767: <li><preduedate> everything inside the tag is skipped if the 770: 771: problem is after the due date </li> 772: 773: <li><randomlist> the enclosed tags are parsed in a stable random 776: 777: order, optional argument show restricts the number of tags 778: 779: indie that are actually parsed the no more than show. </li> 782: 783: <li><solved> everything inside the tag is skipped if the 786: 787: problem is "not solved" </li> 788: 789: <li><while> implements a while loop, required argument condition 792: 793: is a perl scriptlet that when evaluated results in a true or false value, 794: 795: on true the entirety of the text between the whiles is parsed. The condition 796: 797: is tested again, etc. If false it goes to the next node in the parse. 798: 799: </li> 800: 801: </ul> 802: 803: <li>Structure Tags </li> 804: 805: </ul> 806: 807: These tags give the problem a structure and take care of the recording of 808: 809: data and giving the student messages. 810: 811: <ul type=disc> 812: 813: <ul type=circle> 814: 815: <li><problem> must be the first tag in the file, this tag 818: 819: sets up the header of the webpage and generates the submit buttons, it 820: 821: also handles due dates properly </li> 822: 823: <li><part> must be below <problem> if it is going 826: 827: to be used. It does many of the same tasks as <problem> but allows 828: 829: multiple separate problems to exist in a single file. </li> 830: 831: <li><startouttext><endouttext> these tags are somewhat special, they must have 834: 835: no internal text and occur in pairs. Their use is to mark up the problem 836: 837: so the web editor knows what sections should be edited in a plain text 838: 839: block on the web. </li> 840: 841: </ul> 842: 843: </ul> 844: 845: <h3><a name="_Toc421867128"><script> Functions</a></h3> 846: 847: A list of functions that have been written that are available in the Safe 848: 849: space scripting environment inside a problem. 850: 851: <ul type=disc> 852: 853: <li>sin(x), cos(x), tan(x)</li> 854: 855: <li>asin(x), acos(x), atan(x), atan2(y,x)</li> 856: 857: <li>log(x), log10(x)</li> 858: 859: <li>exp(), pow(x,y), sqrt(x)</li> 860: 861: <li>abs(x), sgn(x)</li> 862: 863: <li>erf(x), erfc(x)</li> 864: 865: <li>ceil(x), floor(x)</li> 866: 867: <li>min(...), max(...)</li> 868: 869: <li>factorial(n)</li> 870: 871: <li>N%M</li> 872: 873: <li>sinh(x), cosh(x), tanh(x)</li> 874: 875: <li>asinh(x), acosh(x), atanh(x)</li> 876: 877: <li>roundto(x,n)</li> 878: 879: <li>web("a","b","c") or web(a,b,c)</li> 880: 881: <li>html("a") or html(a)</li> 882: 883: <li>j0(x), j1(x), jn(n,x), jv(y,x)</li> 884: 885: <li>y0(x), y1(x), yn(n,x), yv(y,x)</li> 886: 887: <li>random</li> 888: 889: <li>choose</li> 890: 891: <li>tex("a","b") or tex(a,b)</li> 892: 893: <li>var_in_tex(a)</li> 894: 895: <li>to_string(x), to_string(x,y)</li> 896: 897: <li>class(), section()</li> 898: 899: <li>name(), student_number()</li> 900: 901: <li>open_date(), due_date(), answer_date()</li> 902: 903: <li>sub_string()</li> 904: 905: <li>array_moments(array)</li> 906: 907: <li>format(x,y),prettyprint(x,y)</li> 908: 909: <li>map(...)</li> 910: 911: <li>caparesponse_check</li> 912: 913: <li>caparesponse_check_list</li> 914: 915: </ul> 916: 917: <h3><a name="_Toc421867129">Detailed descriptions of each function and comparison 918: 919: with CAPA</a></h3> 920: 921: <table border=1 cellpadding=0> 922: 923: <tr> 924: 925: <td width=131 valign=top class="Normal"> CAPA Functions</td> 926: 927: <td width=134 valign=top class="Normal"> LON-CAPA</td> 928: 929: <td width=147 valign=top class="Normal"> Descriptions</td> 930: 931: <td width=101 valign=top class="Normal"> Differences (if any)</td> 932: 933: </tr> 934: 935: <tr> 936: 937: <td width=131 valign=top class="Normal"> sin(x), cos(x), tan(x)</td> 938: 939: <td width=134 valign=top class="Normal"> &sin($x), &cos($x), 940: 941: &tan($x)</td> 942: 943: <td width=147 valign=top class="Normal"> Trigonometric functions where 944: 945: x is in radians. $x can be a pure number, i.e., you can call &sin(3.1415)</td> 946: 947: <td width=101 valign=top class="Normal">  </td> 948: 949: </tr> 950: 951: <tr> 952: 953: <td width=131 valign=top class="Normal"> asin(x), acos(x), atan(x), atan2(y,x)</td> 954: 955: <td width=134 valign=top class="Normal"> &asin($x), &acos($x), 956: 957: &atan($x), &atan2($y,$x)</td> 958: 959: <td width=147 valign=top class="Normal"> Inverse trigonometric functions. 960: 961: Return value is in radians. For asin and acos the value of x must be 962: 963: between -1 and 1. The atan2 returns a value between -pi and pi the sign 964: 965: of which is determined by y. $x and $y can be pure numbers</td> 966: 967: <td width=101 valign=top class="Normal">  </td> 968: 969: </tr> 970: 971: <tr> 972: 973: <td width=131 valign=top class="Normal"> log(x), log10(x)</td> 974: 975: <td width=134 valign=top class="Normal"> &log($x), &log10($x)</td> 976: 977: <td width=147 valign=top class="Normal"> Natural and base-10 logarithm. 978: 979: $x can be a pure number</td> 980: 981: <td width=101 valign=top class="Normal">  </td> 982: 983: </tr> 984: 985: <tr> 986: 987: <td width=131 valign=top class="Normal"> exp(x), pow(x,y), sqrt(x)</td> 988: 989: <td width=134 valign=top class="Normal"> &exp($x), &pow($x,$y), 990: 991: &sqrt($x)</td> 992: 993: <td width=147 valign=top class="Normal"> Exponential, power and square 994: 995: root, i.e.,ex, xy and /x. $x and $y can be pure 996: 997: numbers</td> 998: 999: <td width=101 valign=top class="Normal">  </td> 1000: 1001: </tr> 1002: 1003: <tr> 1004: 1005: <td width=131 valign=top class="Normal"> abs(x), sgn(x)</td> 1006: 1007: <td width=134 valign=top class="Normal"> &abs($x), &sgn($x)</td> 1008: 1009: <td width=147 valign=top class="Normal"> Abs takes the absolute value 1010: 1011: of x while sgn(x) returns 1, 0 or -1 depending on the value of x. For 1012: 1013: x>0, sgn(x) = 1, for x=0, sgn(x) = 0 and for x<0, sgn(x) = -1. 1014: 1015: $x can be a pure number</td> 1016: 1017: <td width=101 valign=top class="Normal">  </td> 1018: 1019: </tr> 1020: 1021: <tr> 1022: 1023: <td width=131 valign=top class="Normal"> erf(x), erfc(x)</td> 1024: 1025: <td width=134 valign=top class="Normal"> &erf($x), &erfc($x)</td> 1026: 1027: <td width=147 valign=top class="Normal"> Error function.  erf = 1028: 1029: 2/sqrt(pi) integral (0,x) et-sq and erfx(x) 1030: 1031: = 1.0 - erf(x).  $x can be a pure number</td> 1034: 1035: <td width=101 valign=top class="Normal">  </td> 1036: 1037: </tr> 1038: 1039: <tr> 1040: 1041: <td width=131 valign=top class="Normal"> ceil(x), floor(x)</td> 1042: 1043: <td width=134 valign=top class="Normal"> &ceil($x), &floor($x)</td> 1044: 1045: <td width=147 valign=top class="Normal"> Ceil function returns an integer 1046: 1047: rounded up whereas floor function returns and integer rounded down. 1048: 1049: If x is an integer than it returns the value of the integer. $x can 1050: 1051: be a pure number</td> 1052: 1053: <td width=101 valign=top class="Normal">  </td> 1054: 1055: </tr> 1056: 1057: <tr> 1058: 1059: <td width=131 valign=top class="Normal"> min(...), max(...)</td> 1060: 1061: <td width=134 valign=top class="Normal"> &min(...), &max(...)</td> 1062: 1063: <td width=147 valign=top class="Normal"> Returns the minimum/ maximum 1064: 1065: value of a list of arguments if the arguments are numbers. If the arguments 1066: 1067: are strings then it returns a string sorted according to the ASCII codes</td> 1068: 1069: <td width=101 valign=top class="Normal">  </td> 1070: 1071: </tr> 1072: 1073: <tr> 1074: 1075: <td width=131 valign=top class="Normal"> factorial(n)</td> 1076: 1077: <td width=134 valign=top class="Normal"> &factorial($n)</td> 1078: 1079: <td width=147 valign=top class="Normal"> Argument (n) must be an integer 1080: 1081: else it will round down. The largest value for n is 170. $n can be a 1082: 1083: pure number</td> 1084: 1085: <td width=101 valign=top class="Normal">  </td> 1086: 1087: </tr> 1088: 1089: <tr> 1090: 1091: <td width=131 valign=top class="Normal"> N%M</td> 1092: 1093: <td width=134 valign=top class="Normal"> $N%$M</td> 1094: 1095: <td width=147 valign=top class="Normal"> N and M are integers and returns 1096: 1097: the remainder (in integer) of N/M. $N and $M can be pure numbers</td> 1098: 1099: <td width=101 valign=top class="Normal">  </td> 1100: 1101: </tr> 1102: 1103: <tr> 1104: 1105: <td width=131 valign=top class="Normal"> sinh(x), cosh(x), tanh(x)</td> 1106: 1107: <td width=134 valign=top class="Normal"> &sinh($x), &cosh($x), 1108: 1109: &tanh($x)</td> 1110: 1111: <td width=147 valign=top class="Normal"> Hyperbolic functions. $x can 1112: 1113: be a pure number</td> 1114: 1115: <td width=101 valign=top class="Normal">  </td> 1116: 1117: </tr> 1118: 1119: <tr> 1120: 1121: <td width=131 valign=top class="Normal"> asinh(x), acosh(x), atanh(x)</td> 1122: 1123: <td width=134 valign=top class="Normal"> &asinh($x), &acosh($x), 1124: 1125: &atanh($x)</td> 1126: 1127: <td width=147 valign=top class="Normal"> Inverse hyperbolic functions. 1128: 1129: $x can be a pure number</td> 1130: 1131: <td width=101 valign=top class="Normal">  </td> 1132: 1133: </tr> 1134: 1135: <tr> 1136: 1137: <td width=131 valign=top class="Normal"> /DIS($x,"nn")</td> 1138: 1139: <td width=134 valign=top class="Normal"> &format($x,"nn")</td> 1140: 1141: <td width=147 valign=top class="Normal"> Display or format $x as nn where 1142: 1143: nn is nF or nE and n is an integer.</td> 1144: 1145: <td width=101 valign=top class="Normal">  The difference is obvious.</td> 1146: 1147: </tr> 1148: 1149: <tr> 1150: 1151: <td width=131 valign=top class="Normal"> Not in CAPA</td> 1152: 1153: <td width=134 valign=top class="Normal"> &prettyprint($x,"nn")</td> 1154: 1155: <td width=147 valign=top class="Normal"> Display or format $x as nn where 1156: 1157: nn is nF or nE and n is an integer. In E mode it will attempt to generate 1158: 1159: a pretty x10^3 rather than a E3 following the number</td> 1160: 1161: <td width=101 valign=top class="Normal">  </td> 1162: 1163: </tr> 1164: 1165: <tr> 1166: 1167: <td width=131 valign=top class="Normal"> roundto(x,n)</td> 1168: 1169: <td width=134 valign=top class="Normal"> &roundto($x,$n)</td> 1170: 1171: <td width=147 valign=top class="Normal"> Rounds a real number to n decimal 1172: 1173: points. $x and $n can be pure numbers</td> 1174: 1175: <td width=101 valign=top class="Normal">  </td> 1176: 1177: </tr> 1178: 1179: <tr> 1180: 1181: <td width=131 valign=top class="Normal"> web("a","b","c") 1182: 1183: or web(a,b,c)</td> 1184: 1185: <td width=134 valign=top class="Normal"> &web("a","b","c") 1186: 1187: or &web($a,$b,$c)</td> 1188: 1189: <td width=147 valign=top class="Normal"> Returns either a, b or c depending 1190: 1191: on the output medium. a is for plain ASCII, b for tex output and c for 1192: 1193: html output</td> 1194: 1195: <td width=101 valign=top class="Normal">  </td> 1196: 1197: </tr> 1198: 1199: <tr> 1200: 1201: <td width=131 valign=top class="Normal"> html("a") or html(a)</td> 1202: 1203: <td width=134 valign=top class="Normal"> &html("a") or 1204: 1205: &html($a)</td> 1206: 1207: <td width=147 valign=top class="Normal"> Output only if the output mode 1208: 1209: chosen is in html format</td> 1210: 1211: <td width=101 valign=top class="Normal">  </td> 1212: 1213: </tr> 1214: 1215: <tr> 1216: 1217: <td width=131 valign=top class="Normal"> jn(m,x)</td> 1218: 1219: <td width=134 valign=top class="Normal"> &j0($x), &j1($x), &jn($m,$x), 1220: 1221: &jv($y,$x)</td> 1222: 1223: <td width=147 valign=top class="Normal"> Bessel functions of the first 1224: 1225: kind with orders 0, 1 and m respectively. For jn(m,x), m must be an 1226: 1227: integer whereas for jv(y,x), y is real. $x can be a pure number. $m 1228: 1229: must be an integer and can be a pure integer number. $y can be a pure 1230: 1231: real number</td> 1232: 1233: <td width=101 valign=top class="Normal"> In CAPA, j0, j1 and jn are contained 1234: 1235: in one function, jn(m,x) where m takes the value of 0, 1 or 2. jv(y,x) 1236: 1237: is new to LON-CAPA.</td> 1238: 1239: </tr> 1240: 1241: <tr> 1242: 1243: <td width=131 valign=top class="Normal"> yn(m,x)</td> 1244: 1245: <td width=134 valign=top class="Normal"> &y0($x), &y1($x), &yn($m,$x), 1246: 1247: &yv($y,$x)</td> 1248: 1249: <td width=147 valign=top class="Normal"> Bessel functions of the second 1250: 1251: kind with orders 0, 1 and m respectively. For yn(m,x), m must be an 1252: 1253: integer whereas for yv(y,x), y is real. $x can be a pure number. $m 1254: 1255: must be an integer and can be a pure integer number. $y can be a pure 1256: 1257: real number</td> 1258: 1259: <td width=101 valign=top class="Normal"> In CAPA, y0, y1 and yn are contained 1260: 1261: in one function, yn(m,x) where m takes the value of 0, 1 or 2. yv(y,x) 1262: 1263: is new to LON-CAPA.</td> 1264: 1265: </tr> 1266: 1267: <tr> 1268: 1269: <td width=131 valign=top class="Normal"> random(l,u,d)</td> 1270: 1271: <td width=134 valign=top class="Normal"> &random($l,$u,$d)</td> 1272: 1273: <td width=147 valign=top class="Normal"> Returns a uniformly distributed 1274: 1275: random number between the lower bound, l and upper bound, u in steps 1276: 1277: of d. $l, $u and $d can be pure numbers</td> 1278: 1279: <td width=101 valign=top class="Normal"> In CAPA, all the 3 arguments 1280: 1281: must be of the same type. However, now you can mix the type</td> 1282: 1283: </tr> 1284: 1285: <tr> 1286: 1287: <td width=131 valign=top class="Normal"> choose(i,...)</td> 1288: 1289: <td width=134 valign=top class="Normal"> &choose($i,...)</td> 1290: 1291: <td width=147 valign=top class="Normal"> Choose the ith item from the 1292: 1293: argument list. i must be an integer greater than 0 and the value of 1294: 1295: i should not exceed the number of items. $i can be a pure integer</td> 1296: 1297: <td width=101 valign=top class="Normal">  </td> 1298: 1299: </tr> 1300: 1301: <tr> 1302: 1303: <td width=131 valign=top class="Normal"> /MAP(seed;w,x,y,z;a,b,c,d)</td> 1304: 1305: <td width=134 valign=top class="Normal"> Option 1 - &map($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) 1306: 1307: or 1308: 1309: Option 2 - &map($seed,\@mappedArray,[$a,$b,$c,$d]) 1310: 1311: Option 3 - @mappedArray = &map($seed,[$a,$b,$c,$d]) 1312: 1313: Option 4 - ($w,$x,$y,$z) = &map($seed,\@a) 1314: 1315: where $a='A' 1316: 1317: $b='B' 1318: 1319: $c='B' 1320: 1321: $d='B' 1322: 1323: $w, $x, $y, and $z are variables</td> 1324: 1325: <td width=147 valign=top class="Normal"> Assigns to the variables $w, 1326: 1327: $x, $y and $z the values of the $a, $b, $c and $c (A, B, C and D). The 1328: 1329: precise value for $w .. depends on the seed. (Option 1 of calling map). 1330: 1331: In option 2, the values of $a, $b .. are mapped into the array, @mappedArray. 1332: 1333: The two options illustrate the different grouping. Options 3 and 4 give 1334: 1335: a consistent way (with other functions) of mapping the items. For each 1336: 1337: option, the group can be passed as an array, for example, [$a,$b,$c,$d] 1338: 1339: => \@a.</td> 1340: 1341: <td width=101 valign=top class="Normal"> In CAPA, the arguments are divided 1342: 1343: into three groups separated by a semicolon ;. In LON-CAPA, the separation 1344: 1345: is done by using [] brackets or using an array @a. Note the backslash 1346: 1347: (\) before the arguments in the second and third groups.</td> 1348: 1349: </tr> 1350: 1351: <tr> 1352: 1353: <td width=131 valign=top class="Normal"> rmap(seed;a,b,c,d;w,x,y,z)</td> 1354: 1355: <td width=134 valign=top class="Normal"> Option 1 - &rmap($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) 1356: 1357: or 1358: 1359: Option 2 - &rmap($seed,\@rmappedArray,[$a,$b,$c,$d]) 1360: 1361: Option 3 - @rmapped_array = &rmap($seed,[$a,$b,$c,$d]) 1362: 1363: Option 4 - ($w,$x,$y,$z) = &rmap($seed,\@a) 1364: 1365: where $a='A' 1366: 1367: $b='B' 1368: 1369: $c='B' 1370: 1371: $d='B' 1372: 1373: $w, $x, $y, and $z are variables</td> 1374: 1375: <td width=147 valign=top class="Normal"> The rmap functions does the 1376: 1377: reverse action of map if the same seed is used in calling map and rmap. 1378: 1379: </td> 1380: 1381: <td width=101 valign=top class="Normal"> In CAPA, the arguments are divided 1382: 1383: into three groups separated by a semicolon ;. In LON-CAPA, the separation 1384: 1385: is done by using [] brackets (with create an unamed vector reference) 1386: 1387: or using an array @a. Note the backslash (\) before the arguments in 1388: 1389: the second and third groups (Which cause Perl to send to variable locations 1390: 1391: rather than the variable values, similar to a C pointer).</td> 1392: 1393: </tr> 1394: 1395: <tr> 1396: 1397: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1398: 1399: <td width=134 valign=top class="Normal"> $a=&xmlparse($string) </td> 1400: 1401: <td width=147 valign=top class="Normal"> Runs the internal parser over 1402: 1403: the argument parsing for display. Warning 1404: 1405: This will result in different strings in different targets. Don't use 1406: 1407: the results of this function as an answer.</td> 1408: 1409: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1410: 1411: </tr> 1412: 1413: <tr> 1414: 1415: <td width=131 valign=top class="Normal"> tex(a,b), tex("a","b")</td> 1416: 1417: <td width=134 valign=top class="Normal"> &tex($a,$b), &tex("a","b")</td> 1418: 1419: <td width=147 valign=top class="Normal"> Returns a if the output mode 1420: 1421: is in tex otherwise returns b</td> 1422: 1423: <td width=101 valign=top class="Normal">  </td> 1424: 1425: </tr> 1426: 1427: <tr> 1428: 1429: <td width=131 valign=top class="Normal"> var_in_tex(a)</td> 1430: 1431: <td width=134 valign=top class="Normal"> &var_in_tex($a)</td> 1432: 1433: <td width=147 valign=top class="Normal"> Equivalent to tex("a","")</td> 1434: 1435: <td width=101 valign=top class="Normal">  </td> 1436: 1437: </tr> 1438: 1439: <tr> 1440: 1441: <td width=131 valign=top class="Normal"> to_string(x), to_string(x,y)</td> 1442: 1443: <td width=134 valign=top class="Normal"> &to_string($x), &to_string($x,$y)</td> 1444: 1445: <td width=147 valign=top class="Normal"> If x is an integer, returns 1446: 1447: a string. If x is real than the output is a string with format given 1448: 1449: by y. For example, if x = 12.3456, &to_string(x,".3F") 1450: 1451: = 12.345 and &to_string(x,".3E") = 1.234E+01.</td> 1452: 1453: <td width=101 valign=top class="Normal">  </td> 1454: 1455: </tr> 1456: 1457: <tr> 1458: 1459: <td width=131 valign=top class="Normal"> capa_id(), class(), section(), 1460: 1461: set(), problem()</td> 1462: 1463: <td width=134 valign=top class="Normal"> &class(), &section()</td> 1464: 1465: <td width=147 valign=top class="Normal"> Returns null string, class descriptive 1466: 1467: name, section number, set number and null string.</td> 1468: 1469: <td width=101 valign=top class="Normal"> capa_id(), set() and problem() 1470: 1471: are no longer used. Currently, they return a null value.</td> 1472: 1473: </tr> 1474: 1475: <tr> 1476: 1477: <td width=131 valign=top class="Normal"> name(), student_number()</td> 1478: 1479: <td width=134 valign=top class="Normal"> &name(), &student_number()</td> 1480: 1481: <td width=147 valign=top class="Normal"> Return the full name in the 1482: 1483: following format: lastname, firstname initial. Student_number returns 1484: 1485: the student 9-alphanumeric string. If undefined, the functions return 1486: 1487: null.</td> 1488: 1489: <td width=101 valign=top class="Normal">  </td> 1490: 1491: </tr> 1492: 1493: <tr> 1494: 1495: <td width=131 valign=top class="Normal"> open_date(), due_date(), answer_date()</td> 1496: 1497: <td width=134 valign=top class="Normal"> &open_date(), &due_date(), 1498: 1499: &answer_date()</td> 1500: 1501: <td width=147 valign=top class="Normal"> Problem open date, due date 1502: 1503: and answer date. The time is also included in 24-hr format.</td> 1504: 1505: <td width=101 valign=top class="Normal"> Output format for time is changed 1506: 1507: slightly. If pass noon, it displays ..pm else it displays ..am. So 23:59 1508: 1509: is displayed as 11:59 pm.</td> 1510: 1511: </tr> 1512: 1513: <tr> 1514: 1515: <td width=131 valign=top class="Normal"> get_seed(), set_seed()</td> 1516: 1517: <td width=134 valign=top class="Normal"> Not implemented</td> 1518: 1519: <td width=147 valign=top class="Normal"> Get and set the random seed.</td> 1520: 1521: <td width=101 valign=top class="Normal">  </td> 1522: 1523: </tr> 1524: 1525: <tr> 1526: 1527: <td width=131 valign=top class="Normal"> sub_string(a,b,c)</td> 1528: 1529: <td width=134 valign=top class="Normal"> &sub_string($a,$b,$c) 1530: 1531: perl  substr function. However, note the differences</td> 1532: 1533: <td width=147 valign=top class="Normal"> Retrieve a portion of string 1534: 1535: a starting from b and length c. For example,  $a = "Welcome 1536: 1537: to LON-CAPA"; $result=&sub_string($a,4,4); then $result is 1538: 1539: "come"</td> 1540: 1541: <td width=101 valign=top class="Normal"> Perl intrinsic function, substr(string,b,c) 1542: 1543: starts counting from 0 (as opposed to 1). In the example to the left, 1544: 1545: substr($a,4,4) returns "ome ".</td> 1546: 1547: </tr> 1548: 1549: <tr> 1550: 1551: <td width=131 valign=top class="Normal"> array[xx]</td> 1552: 1553: <td width=134 valign=top class="Normal"> @arrayname 1554: 1555: Array is intrinsic in perl. To access a specific element use $arrayname[$n] 1556: 1557: where $n is the $n+1 element since the array count starts from 0</td> 1558: 1559: <td width=147 valign=top class="Normal"> "xx" can be a variable 1560: 1561: or a calculation.</td> 1562: 1563: <td width=101 valign=top class="Normal"> In LON-CAPA, an array is defined 1564: 1565: by @arrayname. It is not necessary to specify the dimension of the array. </td> 1566: 1567: </tr> 1568: 1569: <tr> 1570: 1571: <td width=131 valign=top class="Normal"> array_moments(B,A)</td> 1572: 1573: <td width=134 valign=top class="Normal"> @B=&array_moments(@A)</td> 1574: 1575: <td width=147 valign=top class="Normal"> Evaluates the moments of an 1576: 1577: array A and place the result in array B[i] where i = 0 to 4. The contents 1578: 1579: of B are as follows: B[0] = number of elements, B[1] = mean, B[2] = 1580: 1581: variance, B[3] = skewness and B[4] = kurtosis.</td> 1582: 1583: <td width=101 valign=top class="Normal"> In CAPA, the moments are passed 1584: 1585: as an array in the first argument whereas in LON-CAPA, the array containing 1586: 1587: the moments are set equal to the function.</td> 1588: 1589: </tr> 1590: 1591: <tr> 1592: 1593: <td width=131 valign=top class="Normal"> array_max(Name), array_min(Name)</td> 1594: 1595: <td width=134 valign=top class="Normal"> &min(@Name), &max(@Name)</td> 1596: 1597: <td width=147 valign=top class="Normal"> In LON-CAPA to find the maximum 1598: 1599: value of an array, use &max(@arrayname)  and to find the minimum 1600: 1601: value of an array, use &min(@arrayname)</td> 1602: 1603: <td width=101 valign=top class="Normal"> Combined with the min and max 1604: 1605: functions defined earlier.</td> 1606: 1607: </tr> 1608: 1609: <tr> 1610: 1611: <td width=131 valign=top class="Normal"> init_array(Name)</td> 1612: 1613: <td width=134 valign=top class="Normal"> undef @name</td> 1614: 1615: <td width=147 valign=top class="Normal"> To destroy the contents of an 1616: 1617: array, use</td> 1618: 1619: <td width=101 valign=top class="Normal"> Use perl intrinsic undef function.</td> 1620: 1621: </tr> 1622: 1623: <tr> 1624: 1625: <td width=131 valign=top class="Normal"> random_normal (return_array,item_cnt,seed,av,std_dev)</td> 1626: 1627: <td width=134 valign=top class="Normal"> @return_array=&random_normal 1628: 1629: ($item_cnt,$seed,$av,$std_dev)</td> 1630: 1631: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1632: 1633: of normal distribution of average $av and standard deviation $std_dev. 1634: 1635: The distribution is generated from seed $seed</td> 1636: 1637: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1638: 1639: as the first argument whereas in LON-CAPA the results are set equal 1640: 1641: to the function.</td> 1642: 1643: </tr> 1644: 1645: <tr> 1646: 1647: <td width=131 valign=top class="Normal"> random_beta (return_array,item_cnt,seed,aa,bb)</td> 1648: 1649: <td width=134 valign=top class="Normal"> @return_array=&random_beta 1650: 1651: ($item_cnt,$seed,$aa,$bb) 1652: 1653: NOTE: Both $aa and $bb MUST be greater than 1.0E-37.</td> 1654: 1655: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1656: 1657: of beta distribution. The density of beta is: X^($aa-1) *(1-X)^($bb-1) 1658: 1659: /B($aa,$bb) for 0<X<1.</td> 1660: 1661: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1662: 1663: as the first argument whereas in LON-CAPA the results are set equal 1664: 1665: to the function.</td> 1666: 1667: </tr> 1668: 1669: <tr> 1670: 1671: <td width=131 valign=top class="Normal"> random_gamma (return_array,item_cnt,seed,a,r)</td> 1672: 1673: <td width=134 valign=top class="Normal"> @return_array=&random_gamma 1674: 1675: ($item_cnt,$seed,$a,$r) 1676: 1677: NOTE: Both $a and $r MUST be positive.</td> 1678: 1679: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1680: 1681: of gamma distribution. The density of gamma is: ($a**$r)/gamma($r) * 1682: 1683: X**($r-1) * exp(-$a*X).</td> 1684: 1685: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1686: 1687: as the first argument whereas in LON-CAPA the results are set equal 1688: 1689: to the function.</td> 1690: 1691: </tr> 1692: 1693: <tr> 1694: 1695: <td width=131 valign=top class="Normal"> random_exponential (return_array,item_cnt,seed,av)</td> 1696: 1697: <td width=134 valign=top class="Normal"> @return_array=&random_exponential 1698: 1699: ($item_cnt,$seed,$av) 1700: 1701: NOTE: $av MUST be non-negative.</td> 1702: 1703: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1704: 1705: of exponential distribution. </td> 1706: 1707: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1708: 1709: as the first argument whereas in LON-CAPA the results are set equal 1710: 1711: to the function.</td> 1712: 1713: </tr> 1714: 1715: <tr> 1716: 1717: <td width=131 valign=top class="Normal"> random_poisson (return_array,item_cnt,seed,mu)</td> 1718: 1719: <td width=134 valign=top class="Normal"> @return_array=&random_poisson 1720: 1721: ($item_cnt,$seed,$mu) 1722: 1723: NOTE: $mu MUST be non-negative.</td> 1724: 1725: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1726: 1727: of poisson distribution. </td> 1728: 1729: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1730: 1731: as the first argument whereas in LON-CAPA the results are set equal 1732: 1733: to the function.</td> 1734: 1735: </tr> 1736: 1737: <tr> 1738: 1739: <td width=131 valign=top class="Normal"> random_chi (return_array,item_cnt,seed,df)</td> 1740: 1741: <td width=134 valign=top class="Normal"> @return_array=&random_chi 1742: 1743: ($item_cnt,$seed,$df) 1744: 1745: NOTE: $df MUST be positive.</td> 1746: 1747: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1748: 1749: of chi_square distribution with $df degrees of freedom. </td> 1750: 1751: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1752: 1753: as the first argument whereas in LON-CAPA the results are set equal 1754: 1755: to the function.</td> 1756: 1757: </tr> 1758: 1759: <tr> 1760: 1761: <td width=131 valign=top class="Normal"> random_noncentral_chi (return_array,item_cnt,seed,df,nonc)</td> 1762: 1763: <td width=134 valign=top class="Normal"> @return_array=&random_noncentral_chi 1764: 1765: ($item_cnt,$seed,$df,$nonc) 1766: 1767: NOTE: $df MUST be at least 1 and $nonc MUST be non-negative.</td> 1768: 1769: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1770: 1771: of noncentral_chi_square distribution with $df degrees of freedom and 1772: 1773: noncentrality parameter $nonc. </td> 1774: 1775: <td width=101 valign=top class="Normal"> In CAPA the results are passed 1776: 1777: as the first argument whereas in LON-CAPA the results are set equal 1778: 1779: to the function.</td> 1780: 1781: </tr> 1782: 1783: <tr> 1784: 1785: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1786: 1787: <td width=134 valign=top class="Normal"> @return_array=&random_f 1788: 1789: ($item_cnt,$seed,$dfn,$dfd) 1790: 1791: NOTE: Both $dfn and $dfd MUST be positive.</td> 1792: 1793: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1794: 1795: of F (variance ratio) distribution with degrees of freedom $dfn (numerator) 1796: 1797: and $dfd (denominator). </td> 1798: 1799: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1800: 1801: </tr> 1802: 1803: <tr> 1804: 1805: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1806: 1807: <td width=134 valign=top class="Normal"> @return_array=&random_noncentral_f 1808: 1809: ($item_cnt,$seed,$dfn,$dfd,$nonc) 1810: 1811: NOTE: $dfn must be at least 1, $dfd MUST be positive, and $nonc must 1812: 1813: be non-negative.</td> 1814: 1815: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1816: 1817: of noncentral F (variance ratio) distribution with degrees of freedom 1818: 1819: $dfn (numerator) and $dfd (denominator). $nonc is the noncentrality 1820: 1821: parameter. </td> 1822: 1823: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1824: 1825: </tr> 1826: 1827: <tr> 1828: 1829: <td width=131 valign=top class="Normal"> NOT DOCUMENTED IN CAPA</td> 1830: 1831: <td width=134 valign=top class="Normal"> @return_array=&random_multivariate_normal 1832: 1833: ($item_cnt,$seed,\@mean,\@covar) 1834: 1835: NOTE: @mean should be of length p array of real numbers. @covar should 1836: 1837: be a length p array of references to length p arrays of real numbers 1838: 1839: (i.e. a p by p matrix.</td> 1840: 1841: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1842: 1843: of multivariate_normal distribution with mean vector @mean and variance-covariance 1844: 1845: matrix. </td> 1846: 1847: <td width=101 valign=top class="Normal"> Note the backslash before the 1848: 1849: @mean and @covar arrays.</td> 1850: 1851: </tr> 1852: 1853: <tr> 1854: 1855: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1856: 1857: <td width=134 valign=top class="Normal"> @return_array=&random_multinomial 1858: 1859: ($item_cnt,$seed,@p) 1860: 1861: NOTE: $item_cnt is rounded with int() and the result must be non-negative. 1862: 1863: The number of elements in @p must be at least 2.</td> 1864: 1865: <td width=147 valign=top class="Normal"> Returns single observation from 1866: 1867: multinomial distribution with $item_cnt events classified into as many 1868: 1869: categories as the length of @p. The probability of an event being classified 1870: 1871: into category i is given by ith element of @p. The observation is an 1872: 1873: array with length equal to @p, so when called in a scalar context it 1874: 1875: returns the length of @p. The sum of the elements of the obervation 1876: 1877: is equal to $item_cnt.</td> 1878: 1879: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1880: 1881: </tr> 1882: 1883: <tr> 1884: 1885: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1886: 1887: <td width=134 valign=top class="Normal"> @return_array=&random_permutation 1888: 1889: ($item_cnt,@array) </td> 1890: 1891: <td width=147 valign=top class="Normal"> Returns @array randomly permuted.</td> 1892: 1893: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1894: 1895: </tr> 1896: 1897: <tr> 1898: 1899: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1900: 1901: <td width=134 valign=top class="Normal"> @return_array=&random_uniform 1902: 1903: ($item_cnt,$seed,$low,$high) 1904: 1905: NOTE: $low must be less than or equal to $high.</td> 1906: 1907: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1908: 1909: from a uniform distribution. </td> 1910: 1911: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1912: 1913: </tr> 1914: 1915: <tr> 1916: 1917: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1918: 1919: <td width=134 valign=top class="Normal"> @return_array=&random_uniform_integer 1920: 1921: ($item_cnt,$seed,$low,$high) 1922: 1923: NOTE: $low and $high are both passed through int(). $low must be less 1924: 1925: than or equal to $high.</td> 1926: 1927: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1928: 1929: from a uniform distribution in integers. </td> 1930: 1931: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1932: 1933: </tr> 1934: 1935: <tr> 1936: 1937: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1938: 1939: <td width=134 valign=top class="Normal"> @return_array=&random_binomial 1940: 1941: ($item_cnt,$seed,$nt,$p) 1942: 1943: NOTE: $nt is rounded using int() and the result must be non-negative. 1944: 1945: $p must be between 0 and 1 inclusive.</td> 1946: 1947: <td width=147 valign=top class="Normal"> Generate $item_cnt deviates 1948: 1949: from the binomial distribution with $nt trials and the probabilty of 1950: 1951: an event in each trial is $p. </td> 1952: 1953: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1954: 1955: </tr> 1956: 1957: <tr> 1958: 1959: <td width=131 valign=top class="Normal"> NOT IMPLEMENTED IN CAPA</td> 1960: 1961: <td width=134 valign=top class="Normal"> @return_array=&random_negative_binomial 1962: 1963: ($item_cnt,$seed,$ne,$p) 1964: 1965: NOTE: $ne is rounded using int() and the result must be positive. $p 1966: 1967: must be between 0 and 1 exclusive.</td> 1968: 1969: <td width=147 valign=top class="Normal"> Generate an array of $item_cnt 1970: 1971: outcomes generated from negative binomial distribution with $ne events 1972: 1973: and the probabilty of an event in each trial is $p. </td> 1974: 1975: <td width=101 valign=top class="Normal"> New to LON-CAPA</td> 1976: 1977: </tr> 1978: 1979: </table> 1980: 1981: <h3><a name="_Toc421867130"><script> Variables</a></h3> 1982: 1983: <ul type=disc> 1984: 1985: <li>$external::target - set to the current target the xml parser is parsing 1986: 1987: for </li> 1988: 1989: <li>$external::part - set to the id 1990: 1991: of the current problem <part>; zero if there are no <part> </li> 1992: 1993: <li>$external::gradestatus - set to the value of the current resource.partid.solved 1994: 1995: value </li> 1996: 1997: <li>$external::datestatus - set to the current status of the clock either 1998: 1999: CLOSED, CAN_ANSWER, CANNOT_ANSWER, SHOW_ANSWER, or UNCHECKEDOUT </li> 2000: 2001: <li>$external::randomseed - set to the number that was used to seed the random 2002: 2003: number generator </li> 2004: 2005: <li>$pi - set to PI </li> 2006: 2007: <li>$rad2deg - converts radians to degrees </li> 2008: 2009: <li>$deg2rad - converts degrees to radians </li> 2010: 2011: </ul> 2012: 2013: <h3><a name="_Toc421867131">Form internals</a> </h3> 2014: 2015: Form elements used for homework editing/response 2016: 2017: the form is named lonhomework 2018: 2019: <h3><a name="_Toc421867132">Viewing a problem (either CSTR or RES space)</a></h3> 2020: 2021: <ul type=disc> 2022: 2023: <li>grade_target, grade_username, grade_domain, grade_symb - the vaules take 2024: 2025: precedence over the the normal env settings of these, use &Apache::lonxml::whichuser() 2026: 2027: to get back the correct vaues of the items </li> 2028: 2029: <li>HWVAL_response:number - the name of the input elements for each response. 2030: 2031: The response is the response's ID, and the :number part exists only for 2032: 2033: response with multiple foils, and is a unique number in order of the submission 2034: 2035: </li> 2036: 2037: <li>changerandseed - the 'Change' button, only exists right after the Change 2038: 2039: button is clicked </li> 2040: 2041: <li>problemmode - in CSTR, it is either 'View','Edit','EditXML' or 'Analyze' 2042: 2043: depending on the desired view </li> 2044: 2045: <li>rndseed - the currently requested random seed </li> 2046: 2047: <li>showallfoils - if it exists, and we are in CSTR space, the problem should 2048: 2049: ignore <conceptgroup> and the response's max setting and show all 2050: 2051: possible foils </li> 2052: 2053: <li>submit - the name of the Submit button </li> 2054: 2055: <li>submitted - a hidden form parameter that can be used to tell if the student 2056: 2057: has submitted answers or not, if it is set, there should be answers to grade. 2058: 2059: </li> 2060: 2061: </ul> 2062: 2063: <h3><a name="_Toc421867133">Editing a problem (Edit mode)</a></h3> 2064: 2065: tagdepth referes to the current value of the xmlparsers tagdepth couter ($Apache::lonxml::currentdepth) 2066: 2067: Note: the file edit.pm has many helper functions for creating the standard 2068: 2069: elements for editing a tag and it's attributes, all of those functions follow 2070: 2071: these conventions 2072: 2073: <ul type=disc> 2074: 2075: <li>tagdepth_argname - I.E. 1_3.max, a parameter editing value, max is the 2076: 2077: name of the parameter and it is for the third tag inside the first tag </li> 2078: 2079: <li>delete_tagdepth - if set to yes, delete tag tagdepth and all tags inside 2080: 2081: of it </li> 2082: 2083: <li>homework_edit_tagdepth - used by both &Apache::edit::editline and 2084: 2085: &Apache::edit::editfield for the <textarea> and <input> 2086: 2087: form elements they create </li> 2088: 2089: <li>insert_tagdepth - used to request an tag insert, it is set to the id number 2090: 2091: of the requested tag in the %Apache::lonxml::insertlist </li> 2092: 2093: </ul> 2094: 2095: <ul type=disc> 2096: 2097: <li>   </li> 2098: 2099: </ul> 2100: 2101: <h3><a name="_Toc421867134">Symbs</a></h3> 2102: 2103: To identify a specific instance of a resource, LON-CAPA uses symbols or �symbs.� 2104: 2105: These identifiers are built from the URL of the map, the resource number of 2106: 2107: the resource in the map, and the URL of the resource itself. The latter is 2108: 2109: somewhat redundant, but might help if maps change. 2110: 2111: An example is 2112: 2113:  msu/korte/parts/part1.sequence___19___msu/korte/tests/part12.problem 2114: 2115: The respective map entry is 2116: 2117:  <resource 2118: 2119: id="19" src="/res/msu/korte/tests/part12.problem"     2120: 2121: 2122: 2123:   title="Problem 2124: 2125: 2"> 2126: 2127:  </resource> 2128: 2129: Symbs are used by the random number generator, as well as 2130: 2131: to store and restore data specific to a certain instance of for example a 2132: 2133: problem. 2134: 2135: <h3><a name="_Toc421867135">Store / Restore</a></h3> 2136: 2137: 2 important functions in lonnet.pm are &Apache::lonnet::cstore() and &Apache::lonnet:restore() (and 2142: 2143: &Apache::lonnet::store(), which is is the non-critical message twin of cstore). These functions are for handlers to store a perl hash to 2150: 2151: a user�s permanent data space in an easy manner, and to retrieve it again 2152: 2153: on another call. It is expected that a handler would use this once at the 2154: 2155: beginning to retrieve data, and then again once at the end to send only the 2156: 2157: new data back. 2158: 2159: The data is stored in the user�s data directory 2160: 2161: on the user�s homeserver under the ID of the course. 2162: 2163: The hash that is returned by restore will have all of the previous value for all of the elements 2168: 2169: of the hash. 2170: 2171: Example: 2172: 2173: #creating a hash 2174: 2175: my %hash; 2176: 2177: $hash{'foo'}='bar'; 2178: 2179: #storing it 2180: 2181: &Apache::lonnet::cstore(\%hash); 2182: 2183: #changing a value 2184: 2185: $hash{'foo'}='notbar'; 2186: 2187: #adding a new value 2188: 2189: $hash{'bar'}='foo'; 2190: 2191: &Apache::lonnet::cstore(\%hash); 2192: 2193: #retrieving the hash 2194: 2195: my %history=&Apache::lonnet::restore(); 2196: 2197: #print the hash 2198: 2199: foreach my $key (sort(keys(%history))) 2200: 2201: { 2202: 2203:     print("\%history{$key} 2204: 2205: = $history{$key}"); 2206: 2207: } 2208: 2209: Will print out: 2210: 2211: %history{1:foo} = bar 2212: 2213: %history{1:keys} = foo:timestamp 2214: 2215: %history{1:timestamp} 2216: 2217: = 990455579 2218: 2219: %history{2:bar} = foo 2220: 2221: %history{2:foo} = notbar 2222: 2223: %history{2:keys} = foo:bar:timestamp 2224: 2225: %history{2:timestamp} 2226: 2227: = 990455580 2228: 2229: %history{bar} = foo 2230: 2231: %history{foo} = notbar 2232: 2233: %history{timestamp} = 2234: 2235: 990455580 2236: 2237: %history{version} = 2 2238: 2239: Note that the special hash entries keys, 2240: 2241: version and timestamp were 2244: 2245: added to the hash. version will be 2246: 2247: equal to the total number of versions of the data that have been stored. The 2248: 2249: timestamp attribute will be the UNIX time the hash was stored. keys is available in every historical section to list which keys 2254: 2255: were added or changed at a specific historical revision of a hash. 2256: 2257: Warning do not store the hash that restore returns directly. This 2260: 2261: will cause a mess since it will restore the historical keys as if the were 2262: 2263: new keys. I.E. 1:foo will become 1:1:foo etc. 2268: 2269: Calling convention: 2270: 2271:   my %record=&Apache::lonnet::restore($symb,$courseid,$domain,$uname,$home); 2274: 2275:   &Apache::lonnet::cstore(\%newrecord,$symb,$courseid,$domain,$uname,$home); 2278: 2279: Arguments (only %newrecord is required the rest 2280: 2281: are somewhat optional, read the details): 2282: 2283: �      2286: 2287: $symb - a string containing the internal name of the specific instance 2290: 2291: of a resource. Usually this value can be gotten from &Apache::lonnet::symbread($filename). If the argument is blank, it will attempt to use symbread() for it. If the result is ambiguous store/restore will fail. 2300: 2301: 2302: 2303: �      2306: 2307: $courseid - the internal name for a course, usually found in $env{'request.course.id'} which is what will be looked at if no value is passed to 2314: 2315: the functions. 2316: 2317: �      2320: 2321: $domain - the domain that the user belongs to, usually found in $env{'user.domain'} which is what will be looked at if no value is passed to 2328: 2329: the functions. 2330: 2331: �      2334: 2335: $uname - the login name for the user, usually found in $env{'user.name'} which is what will be looked at if no value is passed to 2342: 2343: the functions. 2344: 2345: �      2348: 2349: $home - the homeserver for the user, usually found in $env{'user.home'} but can be easily gotten from a domain and name through &Apache::lonnet::homeserver($uname,$domain). If no value is passed to store/restore the value in %env 2360: 2361: will be used. 2362: 2363: �      2366: 2367: %newrecord - the hash to store being passed by reference 2370: 2371: Return values: 2372: 2373: �      2376: 2377: an empty string - the function was unable to determine exactly where to store 2380: 2381: or restore from. At least one of the "optional" arguments was unable 2382: 2383: to be determined. 2384: 2385: �      2388: 2389: a hash - restore successfully read a old hash for this specific 2392: 2393: user / resource instance. 2394: 2395: �      2398: 2399: no_such_host - the $home specfied 2402: 2403: desn't exist in the network. 2404: 2405: �      2408: 2409: con_delayed - the $home was uncontactable 2412: 2413: at this time. The store will be delayed until it is again available. 2414: 2415: �      2418: 2419: con_failed - the $home was uncontactable 2422: 2423: at this time and store was unable to delay the store until a later time. The 2424: 2425: store failed. 2426: 2427: �      2430: 2431: ok - the store completed succesfully 2434: 2435: �      2438: 2439: error: - remote server failied to store or restore the reason follows 2442: 2443: the : 2446: 2447: <h3><a name="_Toc421867136">Mandatory Homework Data</a></h3> 2448: 2449: <pre> </pre> 2450: 2451: <pre><Provided by &EXT() and set external to the resource, required></pre> 2454: 2455: <pre>resource.partid.opendate   #unix time of when the local machine should let the</pre> 2458: 2459: <pre>                           #student in</pre> 2462: 2463: <pre> </pre> 2466: 2467: <pre>resource.partid.duedate    #unix time of when the local machine should stop</pre> 2470: 2471: <pre>                           #accepting answers</pre> 2474: 2475: <pre> </pre> 2478: 2479: <pre>resource.partid.answerdate #unix time of when the local machine should</pre> 2482: 2483: <pre>                           #provide the correct answer to the student</pre> 2486: 2487: <pre> </pre> 2490: 2491: <pre>resource.partid.weight     # points the problem is worth</pre> 2494: 2495: <pre> </pre> 2498: 2499: <pre>resource.partid.maxtries   # maximum number of attempts the student can have</pre> 2502: 2503: <pre> </pre> 2506: 2507: <pre>resource.partid.type       # type of problem homework can be:</pre> 2510: 2511: <pre>                           # homework - randomized, graded, stored with </pre> 2514: 2515: <pre>                           #            requesting user, full feeback</pre> 2518: 2519: <pre>                           # exam - randomized, graded, stored with </pre> 2522: 2523: <pre>                           #        requesting user, minimal feedback</pre> 2526: 2527: <pre>                           # form - unrandomized, ungraded, stored with </pre> 2530: 2531: <pre>                           #        specified user, full feedback</pre> 2534: 2535: <pre>                           # survey - unrandomized, ungraded, stored with </pre> 2538: 2539: <pre>                           #          requesting user, full feedback</pre> 2542: 2543: <pre> </pre> 2546: 2547: <pre> </pre> 2550: 2551: <pre> </pre> 2554: 2555: <pre><numerical/formula/response needed: (has a default if nonexistant)></pre> 2558: 2559: <pre> </pre> 2562: 2563: <pre>resource.partid.responseid.tol   # lots of possibilities here</pre> 2566: 2567: <pre>                    # percentage, range (inclusive and exclusive),</pre> 2570: 2571: <pre>                     # variable name, etc</pre> 2574: 2575: <pre>                    # 3%</pre> 2578: 2579: <pre>                    # 0.5</pre> 2582: 2583: <pre>                    # .05+</pre> 2586: 2587: <pre>                    # 3%+</pre> 2590: 2591: <pre>                    # 0.5+,.005</pre> 2594: 2595: <pre> </pre> 2598: 2599: <pre>resource.partid.responseid.sig  # one or two comma sepearted integers,    </pre> 2602: 2603: <pre>                                # specifying the number of significatn figures</pre> 2606: 2607: <pre>                                # a student must use</pre> 2610: 2611: <pre> </pre> 2614: 2615: <pre> </pre> 2618: 2619: <pre> </pre> 2622: 2623: <pre><Problem sets using cstore (required):></pre> 2626: 2627: <pre>resource.partid.solved # if not set, problem yet to be viewed</pre> 2630: 2631: <pre>                # incorrect_attempted == incorrect and attempted</pre> 2634: 2635: <pre>                # correct_by_student == correct by student work</pre> 2638: 2639: <pre>                # correct_by_override == correct, instructor override</pre> 2642: 2643: <pre>                # incorrect_by_override == incorrect, instructor override</pre> 2646: 2647: <pre>                # excused == excused, problem no longer counts for student</pre> 2650: 2651: <pre>                # '' (empty) == not attempted</pre> 2654: 2655: <pre>                # ungraded_attempted == an ungraded answer has been</pre> 2658: 2659: <pre>                                          sumbitted and stored</pre> 2662: 2663: <pre>resource.partid.tries  # positive integer of number of unsuccessful attempts</pre> 2666: 2667: <pre>                # made, malformed answers don't count if feedback is</pre> 2670: 2671: <pre>                # on</pre> 2674: 2675: <pre> </pre> 2678: 2679: <pre>resource.partid.awarded # float between 0 and 1, percentage of</pre> 2682: 2683: <pre>                 # resource.weight that the stundent earned.</pre> 2686: 2687: <pre> </pre> 2690: 2691: <pre>resource.partid.award # final detailed award that was applied to the entire</pre> 2694: 2695: <pre>                      # part of the question, check awarddetail below for</pre> 2698: 2699: <pre>                      # possibilities</pre> 2702: 2703: <pre> </pre> 2706: 2707: <pre>resource.partid.previous # boolean, is this submission a previous submission</pre> 2710: 2711: <pre> </pre> 2714: 2715: <pre>resource.partid.responseid.submissons</pre> 2718: 2719: <pre>                    # the student submitted string for the part.response</pre> 2722: 2723: <pre> </pre> 2726: 2727: <pre>resource.partid.responseid.awarddetail</pre> 2730: 2731: <pre>                     # list of all of the results of grading the submissions</pre> 2734: 2735: <pre>                     # in detailed form of the specific failure</pre> 2738: 2739: <pre>                      #Possible values:</pre> 2742: 2743: <pre>                     # EXACT_ANS, APPROX_ANS : student is correct</pre> 2746: 2747: <pre>                     # NO_RESPONSE : student submitted no response</pre> 2750: 2751: <pre>                     # MISSING_ANSWER : student submitted some but not</pre> 2754: 2755: <pre>                     #                   all parts of a response</pre> 2758: 2759: <pre>                     # WANTED_NUMERIC : expected a numeric answer and</pre> 2762: 2763: <pre>                     #                   didn't get one</pre> 2766: 2767: <pre>                      # SIG_FAIL : incorrect number of Significant Figures</pre> 2770: 2771: <pre>                     # UNIT_FAIL : incorrect unit</pre> 2774: 2775: <pre>                     # UNIT_NOTNEEDED : Submitted a unit when one shouldn't</pre> 2778: 2779: <pre>                     # NO_UNIT : needed a unit but none was submitted</pre> 2782: 2783: <pre>                      # BAD_FORMULA : syntax error in submitted formula</pre> 2786: 2787: <pre>                     # INCORRECT : answer was wrong</pre> 2790: 2791: <pre>                     # SUBMITTED : submission wasn't graded</pre> 2794: 2795: <pre>                     # ERROR : unable to get a grade</pre> 2798: 2799: <pre> </pre> 2802: 2803: <pre>resource.partid.responseid.message (optional) (not yet supported)</pre> 2806: 2807: <pre>                       # a message that should be shown to the student</pre> 2810: 2811: <pre> </pre> 2814: 2815: <pre>resource.partid.bonustries (optional) (not yet supported)</pre> 2818: 2819: <pre>                     # if set, added to the maxtries parameter for student </pre> 2822: 2823: <pre>                     # total number of tries overall</pre> 2826: 2827: <pre> </pre> 2828: 2829: <h3><a name="_Toc421867137">Sample Problems</a></h3> 2830: 2831: A Simple Problem 2834: 2835: <problem> 2838: 2839:         2842: 2843: <script type="loncapa/perl"> 2844: 2845: $length=&random(10,99,.1); 2848: 2849: $width=&random(1,10,.01); 2852: 2853: @area=($length*($width*10)); 2856: 2857:         2860: 2861: </script> 2862: 2863: What 2866: 2867: is the area of a box $length mm in length and 2868: 2869: &format($width,"2E") 2872: 2873: cm in width. 2874: 2875:         2878: 2879: <numericalresponse id="11" answer="@area" units="mm^2"> 2880: 2881:                 2884: 2885: <textline></textline> 2886: 2887:                 2890: 2891: <responseparam name="tol" type="tolerance" default="5%"></responseparam> 2892: 2893:         2896: 2897: </numericalresponse> 2898: 2899: </problem> 2902: 2903: A More Complex Problem 2906: 2907: <problem> 2908: 2909: <displayduedate 2910: 2911: /> 2912: 2913: <displaytitle 2914: 2915: /> 2916: 2917: <script type="loncapa/perl"> 2918: 2919: $vF=" 2920: 2921: F1 "; 2922: 2923: $vF1=" 2924: 2925: F1 "; 2926: 2927: $vF2=" 2928: 2929: F2 "; 2930: 2931: $mF="|F|"; 2932: 2933: $F1mag="|F1|"; 2934: 2935: $F2mag="|F2|"; 2936: 2937: $trq1mag="| 2938: 2939: t1|"; 2940: 2941: $trq2mag="| 2942: 2943: t2|"; 2944: 2945: $Q1="Q1"; 2946: 2947: $Q2="Q2"; 2948: 2949: $tau="t"; 2952: 2953: $tau1="t1"; 2956: 2957:    $val=&random(1,4,1); 2958: 2959:    $tp=&choose($val,"her","her","his","his"); 2960: 2961:    $sd=&choose($val,"daughter","niece","nephew","son"); 2962: 2963: </script> 2964: 2965: <startouttext 2966: 2967: /> 2968: 2969: $trq1mag and $trq2mag 2970: 2971: are the magnitudes of the torques produced repectively by 2972: 2973: forces $vF1 and $vF2 2974: 2975: with respect the pivot P. The magnitudes of $vF1 is 2976: 2977: $F1mag and that of 2978: 2979: $vF2 is $F2mag. $Q1 and $Q2 are the locations 2980: 2981: on a rigid body where 2982: 2983: $vF1 and $vF2 act.  2984: 2985: <endouttext /> 2986: 2987: <optionresponse 2988: 2989: max="600"> 2990: 2991:         2992: 2993: <foilgroup options="('Correct','Incorrect','Can not tell')"> 2994: 2995:                 2996: 2997: <conceptgroup concept="Effect of the moment-arm on the torque"> 2998: 2999:                         3000: 3001: <foil name="1a" value="Incorrect"> 3002: 3003:                           3004: 3005: For $F1mag larger than $F2mag , $trq1mag is larger than $trq2mag 3006: 3007:                         3008: 3009: </foil> 3010: 3011:                         3012: 3013: <foil name="1b" value="Incorrect"> 3014: 3015:                           3016: 3017: For $F1mag smaller than $F2mag , $trq1mag is smaller than $trq2mag 3018: 3019:                         3020: 3021: </foil> 3022: 3023:            3024: 3025:              <foil 3026: 3027: name="1c" value="Correct"> 3028: 3029:                           3030: 3031: For $F1mag larger than $F2mag , $trq1mag can be less  than $trq2mag 3032: 3033:                         3034: 3035: </foil> 3036: 3037:                         3038: 3039: <foil name="1d" value="Correct"> 3040: 3041:                           3042: 3043: For $F1mag smaller than $F2mag , $trq1mag can be larger  than $trq2mag 3044: 3045:                         3046: 3047: </foil> 3048: 3049:                 3050: 3051: </conceptgroup> 3052: 3053:                 3054: 3055: <conceptgroup concept="For a given pivot, relation of force vector 3056: 3057: to torque."> 3058: 3059:                         3060: 3061: <foil name="2a" value="Correct"> 3062: 3063:                   3064: 3065: The moment-arm of $vF is the shortest distance from P to the line along $vF 3066: 3067: . 3068: 3069:                         3070: 3071: </foil> 3072: 3073:                         3074: 3075: <foil name="2b" value="Incorrect"> 3076: 3077:                           3078: 3079: The moment-arm of $vF is the shortest distance from P to $vF vector. 3080: 3081:                         3082: 3083: </foil> 3084: 3085:                         3086: 3087: <foil name="2c" value="Correct"> 3088: 3089:                           3090: 3091: The moment-arm of $vF is not the distance from P to Q1. 3092: 3093:                 3094: 3095:         </foil> 3096: 3097:                         3098: 3099: <foil name="2d" value="Incorrect"> 3100: 3101:                           3102: 3103: The moment-arm of $vF is the distance from P to Q1. 3104: 3105:                         3106: 3107: </foil> 3108: 3109:                 3110: 3111: </conceptgroup> 3112: 3113:                 3114: 3115: <conceptgroup concept="Torque is force x moment-arm."> 3116: 3117:                         3118: 3119: <foil name="3a" value="Correct"> 3120: 3121:                           3122: 3123: $trq1mag equals to the product of the moment-arm and $F1mag . 3124: 3125:                       3126: 3127: </foil> 3128: 3129:                         3130: 3131: <foil name="3b" value="Incorrect"> 3132: 3133:                         3134: 3135: $trq1mag equals to $F1mag times the distance from Q1 3136: 3137: to P. 3138: 3139:                         3140: 3141: </foil> 3142: 3143:                         3144: 3145: <foil name="3c" value="Correct"> 3146: 3147:                           3148: 3149: $trq1mag is not equal to the product of $F1mag and the distance from Q1 3150: 3151: to P. 3152: 3153:                         3154: 3155: </foil> 3156: 3157:                         3158: 3159: <foil name="3d" value="Incorrect"> 3160: 3161:                         3162: 3163: $trq1mag is not equal to the product of the moment-arm and $F1mag . 3164: 3165:          3166: 3167:                </foil> 3168: 3169:                 3170: 3171: </conceptgroup> 3172: 3173:                 3174: 3175: <conceptgroup concept="Pivot point is required to calculate torque"> 3176: 3177:                         3178: 3179: <foil name="4a" value="Correct"> 3180: 3181:                          3182: 3183: $tau1 vector depends on the location of P. 3184: 3185:                         3186: 3187: </foil> 3188: 3189:                         3190: 3191: <foil name="4b" value="Incorrect"> 3192: 3193:                          3194: 3195: $tau1 vector does not depend on the location of P. 3196: 3197:                         3198: 3199: </foil> 3200: 3201:                         3202: 3203: <foil name="4c" value="Correct"> 3204: 3205:                          3206: 3207: $tau1 vector has no meaning unless a pivot is selected. 3208: 3209:                         3210: 3211: </foil> 3212: 3213:                         3214: 3215: <foil name="4d" value="Incorrect"> 3216: 3217:                          3218: 3219: $tau1 vector can be determined without selecting P. 3220: 3221:                         3222: 3223: </foil> 3224: 3225:                 3226: 3227: </conceptgroup> 3228: 3229:                 3230: 3231: <conceptgroup concept="torque from 2 forces acting along same line"> 3232: 3233:                         3234: 3235: <foil name="5a" value="Correct"> 3236: 3237:                           3238: 3239: Two equal forces, acting on a body along the same line but at different positions, 3240: 3241: produce equal torques with respect to a given pivot." 3242: 3243:                         3244: 3245: </foil> 3246: 3247:                         3248: 3249: <foil name="5b" value="Incorrect"> 3250: 3251:                           3252: 3253: Two equal forces, along the same line, produce equal torques with respect 3254: 3255: to a given pivot only if they act at the same point on a body." 3256: 3257:                         3258: 3259: </foil> 3260: 3261:                         3262: 3263: <foil name="5c" value="Incorrect"> 3264: 3265:                           3266: 3267: Two equal forces acting on a body along the same line but at different positions, 3268: 3269: produce equal torques for only one pivot." 3270: 3271:                         3272: 3273: </foil> 3274: 3275:                 3276: 3277: </conceptgroup> 3278: 3279:                 3280: 3281: <foil name="6" value="unused"> 3282: 3283:                         3284: 3285: This foil will never display since it is unused. 3286: 3287:                 3288: 3289: </foil> 3290: 3291:         3292: 3293: </foilgroup> 3294: 3295:         3296: 3297: <notsolved> 3298: 3299:                 3300: 3301: <hintgroup> 3302: 3303: Think the definition 3304: 3305: of the torque. The force and the moment-arm respect to the pivot.  3306: 3307:                 3308: 3309: </hintgroup> 3310: 3311:       3312: 3313:   </notsolved> 3314: 3315: </optionresponse> 3316: 3317: </problem> 3318: 3319: <h3>  </h3> 3320: 3321: <img border=0 width=432 height=370 3322: 3323: src="Session%20On2_files/image003.png" v:shapes="_x0000_i1025"> 3324: 3325: Fig. 3.1.1 � Internal Structure of Homework Handler 3328: 3329: </div> 3330: 3331: 3334: 3335: <div class=Section2> </div> 3336: 3337: </body> 3338: 3339: </html> 3340: