1: # The LearningOnline Network with CAPA
2: # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
3: #
4: # $Id: default_homework.lcpm,v 1.159 2011/06/09 15:43:56 www Exp $
5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28: #
29:
30: #init some globals
31: $hidden::RANDOMINIT=0;
32: $pi=atan2(1,1)*4;
33: $rad2deg=180.0/$pi;
34: $deg2rad=$pi/180.0;
35: $"=' ';
36: use strict;
37: {
38: my $n = 0;
39: my $total = 0;
40: my $num_left = 0;
41: my @order;
42: my $type;
43:
44: sub init_permutation {
45: my ($size,$requested_type) = @_;
46: @order = (0..$size-1);
47: $n = $size;
48: $type = $requested_type;
49: if ($type eq 'ordered') {
50: $total = $num_left = 1;
51: } elsif ($type eq 'unordered') {
52: $total = $num_left = &factorial($size);
53: } else {
54: die("Unkown type: $type");
55: }
56: }
57:
58: sub get_next_permutation {
59: if ($num_left == $total) {
60: $num_left--;
61: return \@order;
62: }
63:
64: # Find largest index j with a[j] < a[j+1]
65:
66: my $j = scalar(@order) - 2;
67: while ($order[$j] > $order[$j+1]) {
68: $j--;
69: }
70:
71: # Find index k such that a[k] is smallest integer
72: # greater than a[j] to the right of a[j]
73:
74: my $k = scalar(@order) - 1;
75: while ($order[$j] > $order[$k]) {
76: $k--;
77: }
78:
79: # Interchange a[j] and a[k]
80:
81: @order[($k,$j)] = @order[($j,$k)];
82:
83: # Put tail end of permutation after jth position in increasing order
84:
85: my $r = scalar(@order) - 1;
86: my $s = $j + 1;
87:
88: while ($r > $s) {
89: @order[($s,$r)]=@order[($r,$s)];
90: $r--;
91: $s++;
92: }
93:
94: $num_left--;
95: return(\@order);
96: }
97:
98: sub get_permutations_left {
99: return $num_left;
100: }
101: }
102:
103: sub check_commas {
104: my ($response)=@_;
105: #print("$response ");
106: my @numbers=split(',',$response);
107: #print(" numbers ".join('-',@numbers)." ");
108: if (scalar(@numbers) > 1) {
109: #print(" numbers[0] ".$numbers[0]." ");
110: if (length($numbers[0]) > 3 || length($numbers[0]) == 0) { return -1; }
111: shift(@numbers);
112: #print(" numbers ".scalar(@numbers)." ");
113: while (scalar(@numbers) > 1) {
114: #print(" numbers ".join('-',@numbers)." ");
115: if (length($numbers[0]) != 3) { return -2; }
116: shift(@numbers);
117: }
118: my ($number)=split('\.',$numbers[0]);
119: #print(" number ".$number." ");
120: #print(" numbers[0] ".$numbers[0]." ");
121: if (length($number) != 3) { return -3; }
122: } else {
123: my ($number)=split('\.',$numbers[0]);
124: if (length($number) > 3) { return -4; }
125: }
126: return 1;
127: }
128:
129:
130: sub caparesponse_check {
131: my ($answer,$response)=@_;
132: #not properly used yet: calc
133: #not to be used: $ans_fmt
134: my $type=$LONCAPA::CAPAresponse_args{'type'};
135: my $tol=$LONCAPA::CAPAresponse_args{'tol'};
136: my $sig=$LONCAPA::CAPAresponse_args{'sig'};
137: my $ans_fmt=$LONCAPA::CAPAresponse_args{'format'};
138: my $unit=$LONCAPA::CAPAresponse_args{'unit'};
139: my $calc=$LONCAPA::CAPAresponse_args{'calc'};
140: my $samples=$LONCAPA::CAPAresponse_args{'samples'};
141:
142: my $tol_type=''; # gets it's value from whether tol has a % or not done
143: my $sig_lbound=''; #done
144: my $sig_ubound=''; #done
145:
146: #type's definitons come from capaParser.h
147:
148: #remove leading and trailing whitespace
149: if (!defined($response)) {
150: $response='';
151: }
152: if ($response=~ /^\s|\s$/) {
153: $response=~ s:^\s+|\s+$::g;
154: }
155:
156: if ($type eq 'cs' || $type eq 'ci') {
157: #for string answers make sure all places spaces occur, there is
158: #really only 1 space, in both the answer and the response
159: $answer=~s/ +/ /g;
160: $response=~s/ +/ /g;
161: } elsif ($type eq 'mc') {
162: $answer=~s/[\s,]//g;
163: $response=~s/[\s,]//g;
164: }
165: if ($type eq 'float' && $unit=~/\$/) {
166: if ($response!~/^\$|\$$/) { return ('NO_UNIT', undef); }
167: $response=~s/\$//g;
168: }
169: if ($type eq 'float' && $unit=~/\,/ && (&check_commas($response)<0)) {
170: return "COMMA_FAIL:";
171: }
172: $ans_fmt=~s/\W//g;
173: $unit=~s/[\$,]//g;
174: if ($type eq 'float') { $response=~s/,//g; }
175:
176: if (length($response) > 500) { return ('TOO_LONG',undef); }
177:
178: if ($type eq '' ) {
179: if ( $answer eq ($answer *1.0)) { $type = 2;
180: } else { $type = 3; }
181: } else {
182: if ($type eq 'cs') { $type = 4; }
183: elsif ($type eq 'ci') { $type = 3 }
184: elsif ($type eq 'mc') { $type = 5; }
185: elsif ($type eq 'fml') { $type = 8; }
186: elsif ($type eq 'math') { $type = 9; }
187: elsif ($type eq 'subj') { $type = 7; }
188: elsif ($type eq 'float') { $type = 2; }
189: elsif ($type eq 'int') { $type = 1; }
190: else { return ('ERROR', "Unknown type of answer: $type") }
191: }
192:
193: my $points;
194: my $id_list;
195: #formula type setup the sample points
196: if ($type eq '8') {
197: ($id_list,$points)=split(/@/,$samples);
198: }
199: if ($tol eq '') {
200: $tol=0.0;
201: $tol_type=1; #TOL_ABSOLUTE
202: } else {
203: if ($tol =~ /%$/) {
204: chop $tol;
205: $tol_type=2; #TOL_PERCENTAGE
206: } else {
207: $tol_type=1; #TOL_ABSOLUTE
208: }
209: }
210:
211: ($sig_ubound,$sig_lbound)=&LONCAPA_INTERNAL_get_sigrange($sig);
212:
213: my $reterror="";
214: my $result;
215: if (($type eq '9') || ($type eq '8')) {
216: if ($response=~/\=/) {
217: return ('BAD_FORMULA','Please submit just an expression, not an equation.');
218: } elsif ($response =~ /\,/ and $response !~ /^\s*\{.*\}\s*$/) {
219: return ('BAD_FORMULA');
220: }
221: }
222: if ($type eq '9') {
223: $result = &maxima_check(&maxima_cas_formula_fix($response),&maxima_cas_formula_fix($answer),\$reterror);
224: } else {
225: if ($type eq '8') { # fml type
226: $response = &capa_formula_fix($response);
227: $answer = &capa_formula_fix($answer);
228: }
229: $result = &caparesponse_capa_check_answer($response,$answer,$type,
230: $tol_type,$tol,
231: $sig_lbound,$sig_ubound,
232: $ans_fmt,$unit,$calc,$id_list,
233: $points,$external::randomseed,
234: \$reterror);
235: }
236: if ($result == '1') { $result='EXACT_ANS'; }
237: elsif ($result == '2') { $result='APPROX_ANS'; }
238: elsif ($result == '3') { $result='SIG_FAIL'; }
239: elsif ($result == '4') { $result='UNIT_FAIL'; }
240: elsif ($result == '5') { $result='NO_UNIT'; }
241: elsif ($result == '6') { $result='UNIT_OK'; }
242: elsif ($result == '7') { $result='INCORRECT'; }
243: elsif ($result == '8') { $result='UNIT_NOTNEEDED'; }
244: elsif ($result == '9') { $result='ANS_CNT_NOT_MATCH'; }
245: elsif ($result =='10') { $result='SUB_RECORDED'; }
246: elsif ($result =='11') { $result='BAD_FORMULA'; }
247: elsif ($result =='12' && !$response) { $result='MISSING_ANSWER'; }
248: elsif ($result =='12') { $result='WANTED_NUMERIC'; }
249: elsif ($result =='13') { $result='UNIT_INVALID_INSTRUCTOR'; }
250: elsif ($result =='141') { $result='UNIT_INVALID_STUDENT'; }
251: elsif ($result =='142') { $result='UNIT_INVALID_STUDENT'; }
252: elsif ($result =='143') { $result='UNIT_INVALID_STUDENT'; }
253: elsif ($result =='15') { $result='UNIT_IRRECONCIBLE'; }
254: else {$result = "ERROR: Unknown Result:$result:$@:";}
255:
256: return ($result,$reterror);
257: }
258:
259:
260: sub caparesponse_check_list {
261: my $responses=$LONCAPA::CAPAresponse_args{'response'};
262: &LONCAPA_INTERNAL_DEBUG("args ".join(':',%LONCAPA::CAPAresponse_args));
263: my $type = $LONCAPA::CAPAresponse_args{'type'};
264: my $answerunit=$LONCAPA::CAPAresponse_args{'unit'};
265: &LONCAPA_INTERNAL_DEBUG("Got type :$type: answer unit :$answerunit:\n");
266:
267: my $preprocess=$LONCAPA::CAPAresponse_args{'preprocess'};
268: $preprocess=~s/^\&//;
269:
270: my $num_input_lines =
271: scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}});
272:
273: if ($type ne '' ) {
274: if (scalar(@$responses) < $num_input_lines) {
275: return 'MISSING_ANSWER';
276: }
277: if (scalar(@$responses) > $num_input_lines) {
278: return 'EXTRA_ANSWER';
279: }
280:
281: }
282:
283: foreach my $which (0..($num_input_lines-1)) {
284: my $answer_size =
285: scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}[$which]});
286: if ($type ne ''
287: && $answer_size > 1) {
288: $responses->[$which]=[split(/,/,$responses->[$which])];
289: } else {
290: $responses->[$which]=[$responses->[$which]];
291: }
292: }
293: foreach my $which (0..($num_input_lines-1)) {
294: my $answer_size =
295: scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}[$which]});
296: my $response_size =
297: scalar(@{$responses->[$which]});
298: if ($answer_size > $response_size) {
299: return 'MISSING_ANSWER';
300: }
301: if ($answer_size < $response_size) {
302: return 'EXTRA_ANSWER';
303: }
304: }
305:
306: my $unit;
307: my ($allowalgebra)=($LONCAPA::CAPAresponse_args{'allowalgebra'}=~/^(yes|1|on)$/i);
308: if ($type eq 'float' || $type eq '') {
309: #for numerical problems split off the unit
310: my $part1;
311: my $part2;
312: if ($allowalgebra) {
313: ($part1,$part2)=($responses->[0][-1]=~ /^(.*[^\s])\s+([^\s]+)$/);
314: } else {
315: ($part1,$part2)=($responses->[0][-1]=~ /^([\d\.\,\s\$]*(?:(?:[xX\*]10[\^\*]*|[eE]*)[\+\-]*\d*)*(?:^|\S)\d+)([\$\s\w\^\*\/\(\)\+\-]*[^\d\.\s\,][\$\s\w\^\*\/\(\)\+\-]*)$/);
316: }
317: if (defined($part1) && defined($part2)) {
318: $responses->[0][-1]=$part1;
319: $unit=&capa_formula_fix($part2);
320: my $customunits=$LONCAPA::CAPAresponse_args{'customunits'};
321: foreach my $replacement (split(/\s*\,\s*/,$customunits)) {
322: my ($which,$what)=split(/\s*\=\s*/,$replacement);
323: if ((defined($which)) && (defined($what))) {
324: $what=&capa_formula_fix($what);
325: $unit=~s/$which/\($what\)/g;
326: }
327: }
328: }
329: }
330: $unit=~s/\s//;
331: my $error;
332: foreach my $response (@$responses) {
333: foreach my $element (@$response) {
334: # See if we have preprocessor
335: if ($preprocess=~/\S/) {
336: if (defined(&$preprocess)) {
337: no strict 'refs';
338: $element=&$preprocess($element,$unit);
339: use strict 'refs';
340: }
341: }
342: if (($type eq 'float') || (($type eq '') && ($unit ne ''))) {
343: $element =~ s/\s//g;
344: }
345: my $appendunit=$unit;
346: # Deal with percentages
347: # unit is unit entered by student, answerunit is unit by author
348: # Deprecated: divide answer by 100 if student entered percent,
349: # but author did not. Too much confusion
350: # if (($unit=~/\%/) && ($answerunit ne '%')) {
351: # $element=$element/100;
352: # $appendunit=~s/\%//;
353: # }
354: # Author entered percent, student did not
355: if (($unit!~/\%/) && ($answerunit=~/\%/)) {
356: $element=$element*100;
357: $appendunit='%'.$appendunit;
358: }
359: # Zero does not need a dimension
360: if (($element==0) && ($unit!~/\w/) && ($answerunit=~/\w/)) {
361: $appendunit=$answerunit;
362: }
363: # Do the math for the student if allowed
364: if ($allowalgebra) {
365: $element=&cas('maxima',$element);
366: }
367: if ($appendunit ne '') {
368: $element .= " $appendunit";
369: }
370: &LONCAPA_INTERNAL_DEBUG("Made response element :$element:");
371: }
372: }
373:
374: foreach my $thisanswer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) {
375: if (!defined($thisanswer)) {
376: return ('ERROR','answer was undefined');
377: }
378: }
379:
380: my $allow_control_char = 0;
381: my $control_chars_removed = 0;
382: my $ansstring;
383: if ($type eq 'cs' || $type eq 'ci') {
384: if (ref($LONCAPA::CAPAresponse_answer->{'answers'}) eq 'ARRAY') {
385: foreach my $strans (@{$LONCAPA::CAPAresponse_answer->{'answers'}}) {
386: if (ref($strans) eq 'ARRAY') {
387: $ansstring = join("\0",@{$strans});
388: foreach my $item (@{$strans}) {
389: if ($item =~ /[\000-\037]/) {
390: $allow_control_char = 1;
391: }
392: }
393: }
394: }
395: }
396: }
397:
398: # &LONCAPA_INTERNAL_DEBUG(&LONCAPA_INTERNAL_Dumper($responses));
399: my %memoized;
400: if ($LONCAPA::CAPAresponse_answer->{'type'} eq 'ordered') {
401: for (my $i=0; $i<scalar(@$responses);$i++) {
402: my $answer = $LONCAPA::CAPAresponse_answer->{'answers'}[$i];
403: my $response = $responses->[$i];
404: my $key = "$answer\0$response";
405: my (@awards,@msgs);
406: for (my $j=0; $j<scalar(@$response); $j++) {
407: if ($type eq 'cs' || $type eq 'ci') {
408: unless ($allow_control_char) {
409: if ($response->[$j] =~ /[\000-\037]/) {
410: $response->[$j] =~ s/[\000-\037]//g;
411: $control_chars_removed = 1;
412: }
413: }
414: }
415: # See if we have preprocessor for string responses
416: if (($preprocess=~/\S/) && ($type eq 'cs' || $type eq 'ci')) {
417: if (defined(&$preprocess)) {
418: no strict 'refs';
419: $response->[$j]=&$preprocess($response->[$j]);
420: use strict 'refs';
421: }
422: }
423:
424: my ($award,$msg) = &caparesponse_check($answer->[$j],
425: $response->[$j]);
426: if ($type eq 'cs' || $type eq 'ci') {
427: $error = &verify_stringresponse($type,$award,$response->[$j],
428: $answer->[$j]);
429: }
430: push(@awards,$award);
431: push(@msgs, $msg);
432: }
433: my ($award,$msg) =
434: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs);
435: $memoized{$key} = [$award,$msg];
436: }
437: } else {
438: #FIXME broken with unorder responses where one is a <value>
439: # and the other is a <vector> (need to delay parse til
440: # inside the loop?)
441: foreach my $response (@$responses) {
442: my $response_size = scalar(@{$response});
443: foreach my $answer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) {
444: my $key = "$answer\0$response";
445: my $answer_size = scalar(@{$answer});
446: my ($award,$msg);
447: if ($answer_size > $response_size) {
448: $award = 'MISSING_ANSWER';
449: } elsif ($answer_size < $response_size) {
450: $award = 'EXTRA_ANSWER';
451: } else {
452: my (@awards,@msgs);
453: for (my $j=0; $j<scalar(@$response); $j++) {
454: if ($type eq 'cs' || $type eq 'ci') {
455: unless ($allow_control_char) {
456: if ($response->[$j] =~ /[\000-\037]/) {
457: $response->[$j] =~ s/[\000-\037]//g;
458: $control_chars_removed = 1;
459: }
460: }
461: }
462: # See if we have preprocessor
463: if (($preprocess=~/\S/) && ($type eq 'cs' || $type eq 'ci')) {
464: if (defined(&$preprocess)) {
465: no strict 'refs';
466: $response->[$j]=&$preprocess($response->[$j]);
467: use strict 'refs';
468: }
469: }
470:
471: my ($award,$msg) = &caparesponse_check($answer->[$j],
472: $response->[$j]);
473: if ($type eq 'cs' || $type eq 'ci') {
474: $error = &verify_stringresponse($type,$award,$response->[$j],
475: $answer->[$j]);
476: }
477: push(@awards,$award);
478: push(@msgs, $msg);
479: }
480: ($award,$msg) =
481: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs);
482: }
483: $memoized{$key} = [$award,$msg];
484: }
485: }
486: }
487:
488: my ($final_award,$final_msg);
489: &init_permutation(scalar(@$responses),
490: $LONCAPA::CAPAresponse_answer->{'type'});
491:
492: # possible FIXMEs
493: # - significant time is spent calling non-safe space routine
494: # from safe space
495: # - early outs could be possible with classifying awards is to stratas
496: # and stopping as so as hitting the top strata
497: # - some early outs also might be possible with check ing the
498: # memoized hash of results (is correct even possible? etc.)
499:
500: my (@final_awards,@final_msg);
501: while( &get_permutations_left() ) {
502: my $order = &get_next_permutation();
503: my (@awards, @msgs, $i);
504: foreach my $thisanswer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) {
505: my $key = "$thisanswer\0".$responses->[$order->[$i]];
506: push(@awards,$memoized{$key}[0]);
507: push(@msgs,$memoized{$key}[1]);
508: $i++;
509:
510: }
511: &LONCAPA_INTERNAL_DEBUG(" all awards ".join(':',@awards));
512:
513: my ($possible_award,$possible_msg) =
514: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs);
515: &LONCAPA_INTERNAL_DEBUG(" pos awards ".$possible_award);
516: push(@final_awards,$possible_award);
517: push(@final_msg,$possible_msg);
518: }
519:
520: &LONCAPA_INTERNAL_DEBUG(" all final_awards ".join(':',@final_awards));
521: my ($final_award,$final_msg) =
522: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@final_awards,\@final_msg,undef,1);
523: return ($final_award,$final_msg,$error,$control_chars_removed,$ansstring);
524: }
525:
526: sub verify_stringresponse {
527: my ($type,$award,$resp,$ans) = @_;
528: return if ($award eq 'EXACT_ANS');
529: my $error;
530: if ($resp =~ /^\s|\s$/) {
531: $resp =~ s{^\s+|\s+$}{}g;
532: }
533: if ($ans =~ /^\s|\s$/) {
534: $ans =~ s{^\s+|\s+$}{}g;
535: }
536: if ($type eq 'ci') {
537: $resp = lc($resp);
538: $ans = lc($ans);
539: }
540: if ($resp eq $ans) {
541: if ($award eq 'INCORRECT') {
542: $error = 'MISGRADED';
543: }
544: }
545: return $error;
546: }
547:
548: sub cas {
549: my ($system,$input,$library)=@_;
550: my $output;
551: my $dump;
552: if ($system eq 'maxima') {
553: $output=&maxima_eval($input,$library);
554: } elsif ($system eq 'R') {
555: ($output,$dump)=&r_eval($input,$library,0);
556: } else {
557: $output='Error: unrecognized CAS';
558: }
559: return $output;
560: }
561:
562: sub cas_hashref {
563: my ($system,$input,$library)=@_;
564: if ($system eq 'maxima') {
565: return 'Error: unsupported CAS';
566: } elsif ($system eq 'R') {
567: return &r_eval($input,$library,1);
568: } else {
569: return 'Error: unrecognized CAS';
570: }
571: }
572:
573: #
574: # cas_hashref_entry takes a list of indices and gets the entry in a hash generated by Rreturn.
575: # Call: cas_hashref_entry(Rvalue, index1, index2, ...) where Rvalue is a hash returned by Rreturn.
576: # Rentry will return the first scalar value it encounters (ignoring excess indices).
577: # If an invalid key is given, it returns undef.
578: #
579: sub cas_hashref_entry {
580: return &Rentry(@_);
581: }
582:
583: #
584: # cas_hashref_array takes a list of indices and gets a column array from a hash generated by Rreturn.
585: # Call: cas_hashref_array(Rvalue, index1, index2, ...) where Rvalue is a hash returned by Rreturn.
586: # If an invalid key is given, it returns undef.
587: #
588: sub cas_hashref_array {
589: return &Rarray(@_);
590: }
591:
592: sub tex {
593: if ( $external::target eq "tex" ) {
594: return $_[0];
595: } else {
596: return $_[1];
597: }
598: }
599:
600: sub var_in_tex {
601: if ( $external::target eq "tex" ) {
602: return $_[0];
603: } else {
604: return "";
605: }
606: }
607:
608: sub web {
609: if ( $external::target eq "tex" ) {
610: return $_[1];
611: } else {
612: if ( $external::target eq "web" || $external::target eq "answer") {
613: return $_[2];
614: } else {
615: return $_[0];
616: }
617: }
618: }
619:
620: sub html {
621: if ( $external::target eq "web" ) {
622: return shift;
623: }
624: }
625:
626: sub hinton {
627: return 0;
628: }
629:
630: sub random {
631: my ($start,$end,$step)=@_;
632: if ( ! $hidden::RANDOMINIT ) {
633: if ($external::randomseed == 0) { $external::randomseed=1; }
634: if ($external::randomseed =~/,/) {
635: my ($num1,$num2)=split(/,/,$external::randomseed);
636: &random_set_seed(1,abs($num1));
637: } elsif ($external::randomseed =~/:/) {
638: my ($num1,$num2)=split(/:/,$external::randomseed);
639: &random_set_seed(abs($num1),abs($num2));
640: } else {
641: &random_set_seed(1,int(abs($external::randomseed)));
642: }
643: &math_random_uniform();
644: $hidden::RANDOMINIT=1;
645: }
646: if (!defined($step)) { $step=1; }
647: my $num=1+int(($end-$start)/$step);
648: my $result=$start + int(&math_random_uniform() * $num)*$step;
649: return $result;
650: }
651:
652: sub random_normal {
653: my ($item_cnt,$seed,$av,$std_dev) = @_;
654: my @oldseed=&random_get_seed();
655: my @retArray;
656: &random_set_seed_from_phrase($seed);
657: @retArray=&math_random_normal($item_cnt,$av,$std_dev);
658: &random_set_seed(@oldseed);
659: return @retArray;
660: }
661:
662: sub random_beta {
663: my ($item_cnt,$seed,$aa,$bb) = @_;
664: my @oldseed=&random_get_seed();
665: my @retArray;
666: &random_set_seed_from_phrase($seed);
667: @retArray=&math_random_beta($item_cnt,$aa,$bb);
668: &random_set_seed(@oldseed);
669: return @retArray;
670: }
671:
672: sub random_gamma {
673: my ($item_cnt,$seed,$a,$r) = @_;
674: my @oldseed=&random_get_seed();
675: my @retArray;
676: &random_set_seed_from_phrase($seed);
677: @retArray=&math_random_gamma($item_cnt,$a,$r);
678: &random_set_seed(@oldseed);
679: return @retArray;
680: }
681:
682: sub random_exponential {
683: my ($item_cnt,$seed,$av) = @_;
684: my @oldseed=&random_get_seed();
685: my @retArray;
686: &random_set_seed_from_phrase($seed);
687: @retArray=&math_random_exponential($item_cnt,$av);
688: &random_set_seed(@oldseed);
689: return @retArray;
690: }
691:
692: sub random_poisson {
693: my ($item_cnt,$seed,$mu) = @_;
694: my @oldseed=&random_get_seed();
695: my @retArray;
696: &random_set_seed_from_phrase($seed);
697: @retArray=&math_random_poisson($item_cnt,$mu);
698: &random_set_seed(@oldseed);
699: return @retArray;
700: }
701:
702: sub random_chi {
703: my ($item_cnt,$seed,$df) = @_;
704: my @oldseed=&random_get_seed();
705: my @retArray;
706: &random_set_seed_from_phrase($seed);
707: @retArray=&math_random_chi_square($item_cnt,$df);
708: &random_set_seed(@oldseed);
709: return @retArray;
710: }
711:
712: sub random_noncentral_chi {
713: my ($item_cnt,$seed,$df,$nonc) = @_;
714: my @oldseed=&random_get_seed();
715: my @retArray;
716: &random_set_seed_from_phrase($seed);
717: @retArray=&math_random_noncentral_chi_square($item_cnt,$df,$nonc);
718: &random_set_seed(@oldseed);
719: return @retArray;
720: }
721:
722: sub random_f {
723: my ($item_cnt,$seed,$dfn,$dfd) = @_;
724: my @oldseed=&random_get_seed();
725: my @retArray;
726: &random_set_seed_from_phrase($seed);
727: @retArray=&math_random_f($item_cnt,$dfn,$dfd);
728: &random_set_seed(@oldseed);
729: return @retArray;
730: }
731:
732: sub random_noncentral_f {
733: my ($item_cnt,$seed,$dfn,$dfd,$nonc) = @_;
734: my @oldseed=&random_get_seed();
735: my @retArray;
736: &random_set_seed_from_phrase($seed);
737: @retArray=&math_random_noncentral_f($item_cnt,$dfn,$dfd,$nonc);
738: &random_set_seed(@oldseed);
739: return @retArray;
740: }
741:
742: sub random_multivariate_normal {
743: my ($item_cnt,$seed,$mean,$covar) = @_;
744: my @oldseed=&random_get_seed();
745: &random_set_seed_from_phrase($seed);
746: my @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar);
747: &random_set_seed(@oldseed);
748: return @retArray;
749: }
750:
751: sub random_multinomial {
752: my ($item_cnt,$seed,@p) = @_;
753: my @oldseed=&random_get_seed();
754: my @retArray;
755: &random_set_seed_from_phrase($seed);
756: my @retArray=&math_random_multinomial($item_cnt,@p);
757: &random_set_seed(@oldseed);
758: return @retArray;
759: }
760:
761: sub random_permutation {
762: my ($seed,@inArray) = @_;
763: my @oldseed=&random_get_seed();
764: my @retArray;
765: &random_set_seed_from_phrase($seed);
766: @retArray=&math_random_permutation(@inArray);
767: &random_set_seed(@oldseed);
768: return @retArray;
769: }
770:
771: sub random_uniform {
772: my ($item_cnt,$seed,$low,$high) = @_;
773: my @oldseed=&random_get_seed();
774: my @retArray;
775: &random_set_seed_from_phrase($seed);
776: @retArray=&math_random_uniform($item_cnt,$low,$high);
777: &random_set_seed(@oldseed);
778: return @retArray;
779: }
780:
781: sub random_uniform_integer {
782: my ($item_cnt,$seed,$low,$high) = @_;
783: my @oldseed=&random_get_seed();
784: my @retArray;
785: &random_set_seed_from_phrase($seed);
786: @retArray=&math_random_uniform_integer($item_cnt,$low,$high);
787: &random_set_seed(@oldseed);
788: return @retArray;
789: }
790:
791: sub random_binomial {
792: my ($item_cnt,$seed,$nt,$p) = @_;
793: my @oldseed=&random_get_seed();
794: my @retArray;
795: &random_set_seed_from_phrase($seed);
796: @retArray=&math_random_binomial($item_cnt,$nt,$p);
797: &random_set_seed(@oldseed);
798: return @retArray;
799: }
800:
801: sub random_negative_binomial {
802: my ($item_cnt,$seed,$ne,$p) = @_;
803: my @oldseed=&random_get_seed();
804: my @retArray;
805: &random_set_seed_from_phrase($seed);
806: @retArray=&math_random_negative_binomial($item_cnt,$ne,$p);
807: &random_set_seed(@oldseed);
808: return @retArray;
809: }
810:
811: sub abs { CORE::abs(shift) }
812: sub sin { CORE::sin(shift) }
813: sub cos { CORE::cos(shift) }
814: sub exp { CORE::exp(shift) }
815: sub int { CORE::int(shift) }
816: sub log { CORE::log(shift) }
817: sub atan2 { CORE::atan2($_[0],$_[1]) }
818: sub sqrt { CORE::sqrt(shift) }
819:
820: sub tan { CORE::sin($_[0]) / CORE::cos($_[0]) }
821: #sub atan { atan2($_[0], 1); }
822: #sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
823: #sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) ); }
824:
825: sub log10 { CORE::log($_[0])/CORE::log(10); }
826:
827: sub factorial {
828: my $input = CORE::int(shift);
829: return "Error - unable to take factorial of an negative number ($input)" if $input < 0;
830: return "Error - factorial result is greater than system limit ($input)" if $input > 170;
831: return 1 if $input == 0;
832: my $result = 1;
833: for (my $i=2; $i<=$input; $i++) { $result *= $i }
834: return $result;
835: }
836:
837: sub sgn {
838: return -1 if $_[0] < 0;
839: return 0 if $_[0] == 0;
840: return 1 if $_[0] > 0;
841: }
842:
843: sub min {
844: my @sorted = sort { $a <=> $b || $a cmp $b } @_;
845: return shift @sorted;
846: }
847:
848: sub max {
849: my @sorted = sort { $a <=> $b || $a cmp $b } @_;
850: return pop @sorted;
851: }
852:
853: sub roundto {
854: my ($input,$n) = @_;
855: return sprintf('%.'.$n.'f',$input);
856: }
857:
858: sub to_string {
859: my ($input,$n) = @_;
860: return sprintf($input) if $n eq "";
861: $n = '.'.$n if $n !~ /^\./;
862: return sprintf('%'.$n,$input) if $n ne "";
863: }
864:
865: sub sub_string {
866: my ($str,$start,$len) = @_;
867: return substr($str,$start-1,$len);
868: }
869:
870: sub pow {return $_[0] ** $_[1]; }
871: sub ceil {return (($_[0]-CORE::int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? (CORE::int($_[0])+ 1) : CORE::int($_[0])); }
872: sub floor {return (($_[0]-CORE::int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? CORE::int($_[0]) : (CORE::int($_[0])-1)); }
873: #sub floor {return int($_[0]); }
874:
875: sub format {
876: my ($value,$fmt)=@_;
877: my ($dollarmode,$commamode,$alwaysperiod,$options);
878: if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; }
879: #if ($options =~ /\$/) { $dollamode=1; }
880: #if ($options =~ /,/) { $commamode=1; }
881: if ($options =~ /\./) { $alwaysperiod=1; }
882: my $result;
883: if ($fmt=~/s$/i) {
884: $result=&format_significant_figures($value,$fmt);
885: } else {
886: $fmt=~s/e/E/g;
887: $result=sprintf('%.'.$fmt,$value);
888: if ($alwaysperiod && $fmt eq '0f') { $result .='.'; }
889: $result=~s/(E[+-]*)0/$1/;
890: }
891: #if ($dollarmode) {$result=&dollarformat($result);}
892: #if ($commamode) {$result=&commaformat($result);}
893: return $result;
894: }
895:
896: sub chemparse {
897: my ($reaction) = @_;
898: my @tokens = split(/(\s\+|\->|<=>|<\-|\.)/,$reaction);
899: my $formula = '';
900: foreach my $token (@tokens) {
901: if ($token eq '->' ) {
902: $formula .= '<m>\ensuremath{\rightarrow}</m> ';
903: next;
904: }
905: if ($token eq '<-' ) {
906: $formula .= '<m>\ensuremath{\leftarrow}</m> ';
907: next;
908: }
909: if ($token eq '<=>') {
910: if ($external::target eq 'web' &&
911: &EXT('request.browser.unicode')) {
912: $formula .= '⇌ ';
913: } else {
914: $formula .= &web('<=> ','<m>\ensuremath{\rightleftharpoons}</m> ',
915: '<=> ');
916: }
917: next;
918: }
919: if ($token eq '.') {
920: $formula =~ s/(\ \;| )$//;
921: $formula .= '·';
922: next;
923: }
924: $token =~ /^\s*([\d|\/]*(?:&frac\d\d)?)(.*)/;
925: $formula .= $1 if ($1 ne '1'); # stoichiometric coefficient
926:
927: my $molecule = $2;
928: # subscripts
929: $molecule =~ s|(?<=[a-zA-Z\)\]\s])(\d+)|<sub>$1</sub>|g;
930: # superscripts
931: $molecule =~ s|\^(\d*[+\-]*)|<sup>$1</sup>|g;
932: # strip whitespace
933: $molecule =~ s/\s*//g;
934: # forced space
935: $molecule =~ s/_/ /g;
936: $molecule =~ s/-/−/g;
937: $formula .= $molecule.' ';
938: }
939: # get rid of trailing space
940: $formula =~ s/(\ \;| )$//;
941: return &xmlparse($formula);
942: }
943:
944: sub prettyprint {
945: my ($value,$fmt,$target)=@_;
946: my $result;
947: if (!$target) { $target = $external::target; }
948: if ($fmt =~ /chem/i) { return(&chemparse($value)); }
949: my ($dollarmode,$commamode,$alwaysperiod,$options);
950: if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; }
951: if ($options =~ /\$/) { $dollarmode=1; }
952: if ($options =~ /,/) { $commamode=1; }
953: if ($options =~ /\./) { $alwaysperiod=1; }
954: if ($fmt=~/s$/i) {
955: $value=&format_significant_figures($value,$fmt);
956: } elsif ($fmt) {
957: $value=sprintf('%.'.$fmt,$value);
958: }
959: if ($alwaysperiod && $fmt eq '0f') {
960: if ($target eq 'tex') {
961: $value .='\\ensuremath{.}';
962: } else {
963: $value .='.';
964: }
965: }
966: if ($value =~ /([0-9\.\-\+]+)E([0-9\-\+]+)/i ) {
967: my $frac=$1;
968: if ($dollarmode) { $frac=&dollarformat($frac); }
969: if ($commamode) { $frac=&commaformat($frac); }
970: my $exponent=$2;
971: $exponent=~s/^\+0*//;
972: $exponent=~s/^-0*/-/;
973: $exponent=~s/^-0*/-/;
974: if ($exponent eq '-') { undef($exponent); }
975: if ($exponent) {
976: if ($target eq 'web') {
977: $result=$frac.'×10<sup>'.$exponent.'</sup>';
978: } elsif ($target eq 'tex') {
979: $result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
980: } else {
981: $result=$value;
982: }
983: } else {
984: $result=$frac;
985: }
986: } else {
987: $result=$value;
988: if ($dollarmode) { $result=&dollarformat($result,$target); }
989: elsif ($commamode) { $result=&commaformat($result,$target); }
990: }
991: return $result;
992: }
993:
994: sub commaformat {
995: my ($number,$target) = @_;
996: if ($number =~ /\./) {
997: while ($number =~ /([^0-9]*)([0-9]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*)$/) {
998: $number = $1.$2.','.$3.$4;
999: }
1000: } else {
1001: while ($number =~ /^([^0-9]*)([0-9]+)([^,][^,][^,])([,0-9]*)$/) {
1002: $number = $1.$2.','.$3.$4;
1003: }
1004: }
1005: return $number;
1006: }
1007:
1008: sub dollarformat {
1009: my ($number,$target) = @_;
1010: if (!$target) { $target = $external::target; }
1011: $number=&commaformat($number,$target);
1012: if ($target eq 'tex') {
1013: $number='\$'.$number; #' stupid emacs
1014: } else {
1015: $number='$'.$number; #' stupid emacs
1016: }
1017: return $number;
1018: }
1019:
1020: # format of form ns or nS where n is an integer
1021: sub format_significant_figures {
1022: my ($number,$format) = @_;
1023: return '0' if ($number == 0);
1024: # extract number of significant figures needed
1025: my ($sig) = ($format =~ /(\d+)s/i);
1026: # arbitrary choice - suggestions ?? or throw error message?
1027: $sig = 3 if ($sig eq '');
1028: # save the minus sign
1029: my $sign = ($number < 0) ? '-' : '';
1030: $number = abs($number);
1031: # needed to correct for a number greater than 1 (or
1032: my $power = ($number < 1) ? 0 : 1;
1033: # could round up. Take the integer part of log10.
1034: my $x10 = int(log($number)/log(10));
1035: # find number with values left of decimal pt = # of sign figs.
1036: my $xsig = $number*10**($sig-$x10-$power);
1037: # get just digits left of decimal pt - also rounds off correctly
1038: my $xint = sprintf('%.0f',$xsig);
1039: # save any trailing zero's
1040: my ($zeros) = ($xint =~ /(0+)$/);
1041: # return number to original magnitude
1042: my $numSig = $xint*10**($x10-$sig+$power);
1043: # insert trailing zero's if have decimal point
1044: $numSig =~ s/^(\d+)\.(\d+)(\e?(.*)?)$/$1\.$2$zeros$3/;
1045: # put a decimal pt for number ending with 0 and length = # of sig fig
1046: $numSig.='.' if (length($numSig) == $sig && $numSig =~ /0$/);
1047: if (length($numSig) < $sig) {
1048: $numSig.='.'.substr($zeros,0,($sig-length($numSig)));
1049: }
1050: # return number with sign
1051: return $sign.$numSig;
1052:
1053: }
1054:
1055: sub map {
1056: my ($phrase,$dest,$source)=@_;
1057: my @oldseed=&random_get_seed();
1058: my @seed = &random_seed_from_phrase($phrase);
1059: &random_set_seed(@seed);
1060: my $destct = scalar(@$dest);
1061: if (!$source) {
1062: my @output;
1063: my @idx = &math_random_permuted_index($destct);
1064: my $ctr = 0;
1065: while ($ctr < $destct) {
1066: $output[$ctr] = $$dest[$idx[$ctr]];
1067: $ctr++;
1068: }
1069: &random_set_seed(@oldseed);
1070: return @output;
1071: } else {
1072: my $num = scalar(@$source);
1073: my @idx = &math_random_permuted_index($num);
1074: my $ctr = 0;
1075: my $tot = $num;
1076: $tot = $destct if $destct < $num;
1077: if (ref($$dest[0])) {
1078: while ($ctr < $tot) {
1079: ${$$dest[$ctr]} = $$source[$idx[$ctr]];
1080: $ctr++;
1081: }
1082: } else {
1083: while ($ctr < $tot) {
1084: $$dest[$ctr] = $$source[$idx[$ctr]];
1085: $ctr++;
1086: }
1087: }
1088: }
1089: &random_set_seed(@oldseed);
1090: return '';
1091: }
1092:
1093: sub rmap {
1094: my ($phrase,$dest,$source)=@_;
1095: my @oldseed=&random_get_seed();
1096: my @seed = &random_seed_from_phrase($phrase);
1097: &random_set_seed(@seed);
1098: my $destct = scalar(@$dest);
1099: if (!$source) {
1100: my @idx = &math_random_permuted_index($destct);
1101: my $ctr = 0;
1102: my @r_idx;
1103: while ($ctr < $destct) {
1104: $r_idx[$idx[$ctr]] = $ctr;
1105: $ctr++;
1106: }
1107: my @output;
1108: $ctr = 0;
1109: while ($ctr < $destct) {
1110: $output[$ctr] = $$dest[$r_idx[$ctr]];
1111: $ctr++;
1112: }
1113: &random_set_seed(@oldseed);
1114: return @output;
1115: } else {
1116: my $num = scalar(@$source);
1117: my @idx = &math_random_permuted_index($num);
1118: my $ctr = 0;
1119: my $tot = $num;
1120: $tot = $destct if $destct < $num;
1121: my @r_idx;
1122: while ($ctr < $tot) {
1123: $r_idx[$idx[$ctr]] = $ctr;
1124: $ctr++;
1125: }
1126: $ctr = 0;
1127: if (ref($$dest[0])) {
1128: while ($ctr < $tot) {
1129: ${$$dest[$ctr]} = $$source[$r_idx[$ctr]];
1130: $ctr++;
1131: }
1132: } else {
1133: while ($ctr < $tot) {
1134: $$dest[$ctr] = $$source[$r_idx[$ctr]];
1135: $ctr++;
1136: }
1137: }
1138: }
1139: &random_set_seed(@oldseed);
1140: return '';
1141: }
1142:
1143: sub capa_id { return }
1144:
1145: sub problem { return }
1146:
1147: sub name{
1148: my $fullname = &EXT('environment.lastname').', '.&EXT('environment.firstname').' '.&EXT('environment.middlename');
1149: $fullname = "" if $fullname eq ", ";
1150: $fullname =~ s/\%2d/-/g;
1151: return $fullname;
1152: }
1153:
1154: sub student_number {
1155: my $id = &EXT('environment.id');
1156: $id = '' if $id eq "";
1157: return $id;
1158: }
1159:
1160: sub class {
1161: my $course = &EXT('course.description');
1162: $course = '' if $course eq "";
1163: return $course;
1164: }
1165:
1166: sub classid {
1167: my $courseid = &EXT('request.course.id');
1168: $courseid = '' if $courseid eq "";
1169: return $courseid;
1170: }
1171:
1172: sub firstname {
1173: my $firstname = &EXT('environment.firstname');
1174: $firstname = '' if $firstname eq "";
1175: return $firstname;
1176: }
1177:
1178: sub middlename {
1179: my $middlename = &EXT('environment.middlename');
1180: $middlename = '' if $middlename eq "";
1181: return $middlename;
1182: }
1183:
1184:
1185: sub lastname {
1186: my $lastname = &EXT('environment.lastname');
1187: $lastname = '' if $lastname eq "";
1188: return $lastname;
1189: }
1190:
1191: sub sec {
1192: my $sec = &EXT('request.course.sec');
1193: $sec = '' if $sec eq "";
1194: return $sec;
1195: }
1196:
1197: sub submission {
1198: my ($partid,$responseid,$subnumber)=@_;
1199: my $sub='';
1200: if ($subnumber) { $sub=$subnumber.':'; }
1201: return &EXT('user.resource.'.$sub.'resource.'.$partid.'.'.$responseid.'.submission');
1202: }
1203:
1204: sub currentpart {
1205: return $external::part;
1206: }
1207:
1208: sub eval_time {
1209: my ($timestamp)=@_;
1210: unless ($timestamp) { return ''; }
1211: return &locallocaltime($timestamp);
1212: }
1213:
1214: sub open_date {
1215: my ($partid)=@_;
1216: unless ($partid) { $partid=0; }
1217: return &eval_time(&EXT('resource.'.$partid.'.opendate'));
1218: }
1219:
1220: sub due_date {
1221: my ($partid)=@_;
1222: unless ($partid) { $partid=0; }
1223: return &eval_time(&EXT('resource.'.$partid.'.duedate'));
1224: }
1225:
1226: sub answer_date {
1227: my ($partid)=@_;
1228: unless ($partid) { $partid=0; }
1229: return &eval_time(&EXT('resource.'.$partid.'.answerdate'));
1230: }
1231:
1232: sub open_date_epoch {
1233: my ($partid)=@_;
1234: unless ($partid) { $partid=0; }
1235: return &EXT('resource.'.$partid.'.opendate');
1236: }
1237:
1238: sub due_date_epoch {
1239: my ($partid)=@_;
1240: unless ($partid) { $partid=0; }
1241: return &EXT('resource.'.$partid.'.duedate');
1242: }
1243:
1244: sub answer_date_epoch {
1245: my ($partid)=@_;
1246: unless ($partid) { $partid=0; }
1247: return &EXT('resource.'.$partid.'.answerdate');
1248: }
1249:
1250: sub parameter_setting {
1251: my ($which,$partid)=@_;
1252: unless ($partid) { $partid=0; }
1253: return &EXT('resource.'.$partid.'.'.$which);
1254: }
1255:
1256: sub stored_data {
1257: my ($which,$partid)=@_;
1258: unless ($partid) { $partid=0; }
1259: return &EXT('user.resource.resource.'.$partid.'.'.$which);
1260: }
1261:
1262: sub wrong_bubbles {
1263: my ($correct,$lower,$upper,$step,@given)=@_;
1264: my @array=();
1265: my %hash=();
1266: foreach my $new (@given) {
1267: $hash{$new}=1;
1268: }
1269: my $num=int(¶meter_setting('numbubbles',¤tpart()));
1270: unless ($num) { $num=8; }
1271: if ($num>1) {
1272: for (my $i=0;$i<=500;$i++) {
1273: my $new=&random($lower,$upper,$step);
1274: if ($hash{$new}) { next; }
1275: if (abs($new-$correct)<$step) { next; }
1276: $hash{$new}=1;
1277: @array=keys(%hash);
1278: if ($#array+2>=$num) { last; }
1279: }
1280: }
1281: return @array;
1282: }
1283:
1284: sub array_moments {
1285: my @input=@_;
1286: my (@output,$N);
1287: $N=scalar (@input);
1288: $output[0]=$N;
1289: if ($N <= 1) {
1290: $output[1]=$input[0];
1291: $output[1]="Input array not defined" if ($N == 0);
1292: $output[2]="variance undefined for N<=1";
1293: $output[3]="skewness undefined for N<=1";
1294: $output[4]="kurtosis undefined for N<=1";
1295: return @output;
1296: }
1297: my $sum=0;
1298: foreach my $line (@input) {
1299: $sum+=$line;
1300: }
1301: $output[1] = $sum/$N;
1302: my ($x,$sdev,$var,$skew,$kurt) = 0;
1303: foreach my $line (@input) {
1304: $x=$line-$output[1];
1305: $var+=$x**2;
1306: $skew+=$x**3;
1307: $kurt+=$x**4;
1308: }
1309: $output[2]=$var/($N-1);
1310: $sdev=CORE::sqrt($output[2]);
1311: if ($sdev == 0) {
1312: $output[3]="inf-variance=0";
1313: $output[4]="inf-variance=0";
1314: return @output;
1315: }
1316: $output[3]=$skew/($sdev**3*$N);
1317: $output[4]=$kurt/($sdev**4*$N)-3;
1318: return @output;
1319: }
1320:
1321: sub choose {
1322: my $num = $_[0];
1323: return $_[$num];
1324: }
1325:
1326: #&sum1(1,$x,sub { &sum1($_[0],2*$_[0], sub { fact($_[0])**2 })});
1327: #sub sum1 {
1328: # my ($start,$end,$sub)=@_;
1329: # my $sum=0;
1330: # for (my $i=$start;$i<=$end;$i++) {
1331: # $sum+=&$sub($i);
1332: # }
1333: # return $sum
1334: #}
1335:
1336: #&sum2('a',1,$x,'&sum2(\'b\',$a,2*$a, \'&factorial($b)**2\')');
1337: #sub sum2 {
1338: # my ($varname,$start,$end,$line)=@_;
1339: # my $sum=0;
1340: # for (my $i=$start;$i<=$end;$i++) {
1341: # my $func=sub {
1342: # eval("\$".$varname."=$i");
1343: # eval($line);
1344: # };
1345: # $sum+=&$func($i);
1346: # }
1347: # return $sum
1348: #}
1349:
1350: # expiremental idea
1351: sub proper_path {
1352: my ($path)=@_;
1353: if ( $external::target eq "tex" ) {
1354: return '/home/httpd/html'.$path;
1355: } else {
1356: return $path;
1357: }
1358: }
1359:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to default_homework.lcpm CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / loncom / homework