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 1.157 2011/06/08 01:39:28 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 $sig_ubound=''; #done
145:
146:
147: #type's definitons come from capaParser.h
148:
149: #remove leading and trailing whitespace
150: if (!defined($response)) {
151: $response='';
152: }
153: if ($response=~ /^\s|\s$/) {
154: $response=~ s:^\s+|\s+$::g;
155: &LONCAPA_INTERNAL_DEBUG("Removed ws now :$response:");
156: }
157:
158: #&LONCAPA_INTERNAL_DEBUG(" type is $type ");
159: if ($type eq 'cs' || $type eq 'ci') {
160: #for string answers make sure all places spaces occur, there is
161: #really only 1 space, in both the answer and the response
162: $answer=~s/ +/ /g;
163: $response=~s/ +/ /g;
164: } elsif ($type eq 'mc') {
165: $answer=~s/[\s,]//g;
166: $response=~s/[\s,]//g;
167: }
168: if ($type eq 'float' && $unit=~/\$/) {
169: if ($response!~/^\$|\$$/) { return ('NO_UNIT', undef); }
170: $response=~s/\$//g;
171: }
172: if ($type eq 'float' && $unit=~/\,/ && (&check_commas($response)<0)) {
173: return "COMMA_FAIL:";
174: }
175: $ans_fmt=~s/\W//g;
176: $unit=~s/[\$,]//g;
177: if ($type eq 'float') { $response=~s/,//g; }
178:
179: if (length($response) > 500) { return ('TOO_LONG',undef); }
180:
181: if ($type eq '' ) {
182: &LONCAPA_INTERNAL_DEBUG("Didn't find a type :$type: defaulting");
183: if ( $answer eq ($answer *1.0)) { $type = 2;
184: } else { $type = 3; }
185: } else {
186: if ($type eq 'cs') { $type = 4; }
187: elsif ($type eq 'ci') { $type = 3 }
188: elsif ($type eq 'mc') { $type = 5; }
189: elsif ($type eq 'fml') { $type = 8; }
190: elsif ($type eq 'math') { $type = 9; }
191: elsif ($type eq 'subj') { $type = 7; }
192: elsif ($type eq 'float') { $type = 2; }
193: elsif ($type eq 'int') { $type = 1; }
194: else { return ('ERROR', "Unknown type of answer: $type") }
195: }
196:
197: my $points;
198: my $id_list;
199: #formula type setup the sample points
200: if ($type eq '8') {
201: ($id_list,$points)=split(/@/,$samples);
202: &LONCAPA_INTERNAL_DEBUG("Found :$id_list:$points: points in $samples");
203: }
204: if ($tol eq '') {
205: $tol=0.0;
206: $tol_type=1; #TOL_ABSOLUTE
207: } else {
208: if ($tol =~ /%$/) {
209: chop $tol;
210: $tol_type=2; #TOL_PERCENTAGE
211: } else {
212: $tol_type=1; #TOL_ABSOLUTE
213: }
214: }
215:
216: ($sig_ubound,$sig_lbound)=&LONCAPA_INTERNAL_get_sigrange($sig);
217:
218: my $reterror="";
219: my $result;
220: if (($type eq '9') || ($type eq '8')) {
221: if ($response=~/\=/) {
222: return ('BAD_FORMULA','Please submit just an expression, not an equation.');
223: } elsif ($response =~ /\,/ and $response !~ /^\s*\{.*\}\s*$/) {
224: return ('BAD_FORMULA');
225: }
226: }
227: if ($type eq '9') {
228: $result = &maxima_check(&maxima_cas_formula_fix($response),&maxima_cas_formula_fix($answer),\$reterror);
229: } else {
230: if ($type eq '8') { # fml type
231: $response = &capa_formula_fix($response);
232: $answer = &capa_formula_fix($answer);
233: }
234: $result = &caparesponse_capa_check_answer($response,$answer,$type,
235: $tol_type,$tol,
236: $sig_lbound,$sig_ubound,
237: $ans_fmt,$unit,$calc,$id_list,
238: $points,$external::randomseed,
239: \$reterror);
240: }
241: if ($result == '1') { $result='EXACT_ANS'; }
242: elsif ($result == '2') { $result='APPROX_ANS'; }
243: elsif ($result == '3') { $result='SIG_FAIL'; }
244: elsif ($result == '4') { $result='UNIT_FAIL'; }
245: elsif ($result == '5') { $result='NO_UNIT'; }
246: elsif ($result == '6') { $result='UNIT_OK'; }
247: elsif ($result == '7') { $result='INCORRECT'; }
248: elsif ($result == '8') { $result='UNIT_NOTNEEDED'; }
249: elsif ($result == '9') { $result='ANS_CNT_NOT_MATCH'; }
250: elsif ($result =='10') { $result='SUB_RECORDED'; }
251: elsif ($result =='11') { $result='BAD_FORMULA'; }
252: elsif ($result =='12' && !$response) { $result='MISSING_ANSWER'; }
253: elsif ($result =='12') { $result='WANTED_NUMERIC'; }
254: elsif ($result =='13') { $result='UNIT_INVALID_INSTRUCTOR'; }
255: elsif ($result =='141') { $result='UNIT_INVALID_STUDENT'; }
256: elsif ($result =='142') { $result='UNIT_INVALID_STUDENT'; }
257: elsif ($result =='143') { $result='UNIT_INVALID_STUDENT'; }
258: elsif ($result =='15') { $result='UNIT_IRRECONCIBLE'; }
259: else {$result = "ERROR: Unknown Result:$result:$@:";}
260:
261: &LONCAPA_INTERNAL_DEBUG("RetError $reterror: Answer $answer: Response $response: type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|");
262: &LONCAPA_INTERNAL_DEBUG(" $answer $response $result ");
263: return ($result,$reterror);
264: }
265:
266:
267: sub caparesponse_check_list {
268: my $responses=$LONCAPA::CAPAresponse_args{'response'};
269: &LONCAPA_INTERNAL_DEBUG("args ".join(':',%LONCAPA::CAPAresponse_args));
270: my $type = $LONCAPA::CAPAresponse_args{'type'};
271: my $answerunit=$LONCAPA::CAPAresponse_args{'unit'};
272: &LONCAPA_INTERNAL_DEBUG("Got type :$type: answer unit :$answerunit:\n");
273:
274: my $preprocess=$LONCAPA::CAPAresponse_args{'preprocess'};
275: $preprocess=~s/^\&//;
276:
277: my $num_input_lines =
278: scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}});
279:
280: if ($type ne '' ) {
281: if (scalar(@$responses) < $num_input_lines) {
282: return 'MISSING_ANSWER';
283: }
284: if (scalar(@$responses) > $num_input_lines) {
285: return 'EXTRA_ANSWER';
286: }
287:
288: }
289:
290: foreach my $which (0..($num_input_lines-1)) {
291: my $answer_size =
292: scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}[$which]});
293: if ($type ne ''
294: && $answer_size > 1) {
295: $responses->[$which]=[split(/,/,$responses->[$which])];
296: } else {
297: $responses->[$which]=[$responses->[$which]];
298: }
299: }
300: foreach my $which (0..($num_input_lines-1)) {
301: my $answer_size =
302: scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}[$which]});
303: my $response_size =
304: scalar(@{$responses->[$which]});
305: if ($answer_size > $response_size) {
306: return 'MISSING_ANSWER';
307: }
308: if ($answer_size < $response_size) {
309: return 'EXTRA_ANSWER';
310: }
311: }
312:
313: &LONCAPA_INTERNAL_DEBUG("Initial final response :$responses->[0][-1]:");
314: my $unit;
315: my ($allowalgebra)=(¶meter_setting('allowalgebra',¤tpart())=~/^(yes|1|on)$/i);
316: if ($type eq 'float' || $type eq '') {
317: #for numerical problems split off the unit
318: my $part1;
319: my $part2;
320: if ($allowalgebra) {
321: ($part1,$part2)=($responses->[0][-1]=~ /^(.*[^\s])\s+([^\s]+)$/);
322: } else {
323: ($part1,$part2)=($responses->[0][-1]=~ /^([\d\.\,\s\$]*(?:(?:[xX\*]10[\^\*]*|[eE]*)[\+\-]*\d*)*(?:^|\S)\d+)([\$\s\w\^\*\/\(\)\+\-]*[^\d\.\s\,][\$\s\w\^\*\/\(\)\+\-]*)$/);
324: }
325: if (defined($part1) && defined($part2)) {
326: $responses->[0][-1]=$part1;
327: $unit=&capa_formula_fix($part2);
328: &LONCAPA_INTERNAL_DEBUG("Found unit :$unit:");
329: }
330: }
331: &LONCAPA_INTERNAL_DEBUG("Final final response :$responses->[0][-1]:$unit:");
332: $unit=~s/\s//;
333: my $error;
334: foreach my $response (@$responses) {
335: foreach my $element (@$response) {
336: # See if we have preprocessor
337: if ($preprocess=~/\S/) {
338: if (defined(&$preprocess)) {
339: no strict 'refs';
340: $element=&$preprocess($element);
341: use strict 'refs';
342: }
343: }
344: if (($type eq 'float') || (($type eq '') && ($unit ne ''))) {
345: $element =~ s/\s//g;
346: }
347: my $appendunit=$unit;
348: # Deal with percentages
349: # unit is unit entered by student, answerunit is unit by author
350: # Deprecated: divide answer by 100 if student entered percent,
351: # but author did not. Too much confusion
352: # if (($unit=~/\%/) && ($answerunit ne '%')) {
353: # $element=$element/100;
354: # $appendunit=~s/\%//;
355: # }
356: # Author entered percent, student did not
357: if (($unit!~/\%/) && ($answerunit=~/\%/)) {
358: $element=$element*100;
359: $appendunit='%'.$appendunit;
360: }
361: # Zero does not need a dimension
362: if (($element==0) && ($unit!~/\w/) && ($answerunit=~/\w/)) {
363: $appendunit=$answerunit;
364: }
365: # Do the math for the student if allowed
366: if ($allowalgebra) {
367: $element=&cas('maxima',$element);
368: }
369: if ($appendunit ne '') {
370: $element .= " $appendunit";
371: }
372: &LONCAPA_INTERNAL_DEBUG("Made response element :$element:");
373: }
374: }
375:
376: foreach my $thisanswer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) {
377: if (!defined($thisanswer)) {
378: return ('ERROR','answer was undefined');
379: }
380: }
381:
382: my $allow_control_char = 0;
383: my $control_chars_removed = 0;
384: my $ansstring;
385: if ($type eq 'cs' || $type eq 'ci') {
386: if (ref($LONCAPA::CAPAresponse_answer->{'answers'}) eq 'ARRAY') {
387: foreach my $strans (@{$LONCAPA::CAPAresponse_answer->{'answers'}}) {
388: if (ref($strans) eq 'ARRAY') {
389: $ansstring = join("\0",@{$strans});
390: foreach my $item (@{$strans}) {
391: if ($item =~ /[\000-\037]/) {
392: $allow_control_char = 1;
393: }
394: }
395: }
396: }
397: }
398: }
399:
400: # &LONCAPA_INTERNAL_DEBUG(&LONCAPA_INTERNAL_Dumper($responses));
401: my %memoized;
402: if ($LONCAPA::CAPAresponse_answer->{'type'} eq 'ordered') {
403: for (my $i=0; $i<scalar(@$responses);$i++) {
404: my $answer = $LONCAPA::CAPAresponse_answer->{'answers'}[$i];
405: my $response = $responses->[$i];
406: my $key = "$answer\0$response";
407: my (@awards,@msgs);
408: for (my $j=0; $j<scalar(@$response); $j++) {
409: if ($type eq 'cs' || $type eq 'ci') {
410: unless ($allow_control_char) {
411: if ($response->[$j] =~ /[\000-\037]/) {
412: $response->[$j] =~ s/[\000-\037]//g;
413: $control_chars_removed = 1;
414: }
415: }
416: }
417: my ($award,$msg) = &caparesponse_check($answer->[$j],
418: $response->[$j]);
419: if ($type eq 'cs' || $type eq 'ci') {
420: $error = &verify_stringresponse($type,$award,$response->[$j],
421: $answer->[$j]);
422: }
423: push(@awards,$award);
424: push(@msgs, $msg);
425: }
426: my ($award,$msg) =
427: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs);
428: $memoized{$key} = [$award,$msg];
429: }
430: } else {
431: #FIXME broken with unorder responses where one is a <value>
432: # and the other is a <vector> (need to delay parse til
433: # inside the loop?)
434: foreach my $response (@$responses) {
435: my $response_size = scalar(@{$response});
436: foreach my $answer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) {
437: my $key = "$answer\0$response";
438: my $answer_size = scalar(@{$answer});
439: my ($award,$msg);
440: if ($answer_size > $response_size) {
441: $award = 'MISSING_ANSWER';
442: } elsif ($answer_size < $response_size) {
443: $award = 'EXTRA_ANSWER';
444: } else {
445: my (@awards,@msgs);
446: for (my $j=0; $j<scalar(@$response); $j++) {
447: if ($type eq 'cs' || $type eq 'ci') {
448: unless ($allow_control_char) {
449: if ($response->[$j] =~ /[\000-\037]/) {
450: $response->[$j] =~ s/[\000-\037]//g;
451: $control_chars_removed = 1;
452: }
453: }
454: }
455: my ($award,$msg) = &caparesponse_check($answer->[$j],
456: $response->[$j]);
457: if ($type eq 'cs' || $type eq 'ci') {
458: $error = &verify_stringresponse($type,$award,$response->[$j],
459: $answer->[$j]);
460: }
461: push(@awards,$award);
462: push(@msgs, $msg);
463: }
464: ($award,$msg) =
465: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs);
466: }
467: $memoized{$key} = [$award,$msg];
468: }
469: }
470: }
471:
472: my ($final_award,$final_msg);
473: &init_permutation(scalar(@$responses),
474: $LONCAPA::CAPAresponse_answer->{'type'});
475:
476: # possible FIXMEs
477: # - significant time is spent calling non-safe space routine
478: # from safe space
479: # - early outs could be possible with classifying awards is to stratas
480: # and stopping as so as hitting the top strata
481: # - some early outs also might be possible with check ing the
482: # memoized hash of results (is correct even possible? etc.)
483:
484: my (@final_awards,@final_msg);
485: while( &get_permutations_left() ) {
486: my $order = &get_next_permutation();
487: my (@awards, @msgs, $i);
488: foreach my $thisanswer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) {
489: my $key = "$thisanswer\0".$responses->[$order->[$i]];
490: push(@awards,$memoized{$key}[0]);
491: push(@msgs,$memoized{$key}[1]);
492: $i++;
493:
494: }
495: &LONCAPA_INTERNAL_DEBUG(" all awards ".join(':',@awards));
496:
497: my ($possible_award,$possible_msg) =
498: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs);
499: &LONCAPA_INTERNAL_DEBUG(" pos awards ".$possible_award);
500: push(@final_awards,$possible_award);
501: push(@final_msg,$possible_msg);
502: }
503:
504: &LONCAPA_INTERNAL_DEBUG(" all final_awards ".join(':',@final_awards));
505: my ($final_award,$final_msg) =
506: &LONCAPA_INTERNAL_FINALIZEAWARDS(\@final_awards,\@final_msg,undef,1);
507: return ($final_award,$final_msg,$error,$control_chars_removed,$ansstring);
508: }
509:
510: sub verify_stringresponse {
511: my ($type,$award,$resp,$ans) = @_;
512: return if ($award eq 'EXACT_ANS');
513: my $error;
514: if ($resp =~ /^\s|\s$/) {
515: $resp =~ s{^\s+|\s+$}{}g;
516: }
517: if ($ans =~ /^\s|\s$/) {
518: $ans =~ s{^\s+|\s+$}{}g;
519: }
520: if ($type eq 'ci') {
521: $resp = lc($resp);
522: $ans = lc($ans);
523: }
524: if ($resp eq $ans) {
525: if ($award eq 'INCORRECT') {
526: $error = 'MISGRADED';
527: }
528: }
529: return $error;
530: }
531:
532: sub cas {
533: my ($system,$input,$library)=@_;
534: my $output;
535: my $dump;
536: if ($system eq 'maxima') {
537: $output=&maxima_eval($input,$library);
538: } elsif ($system eq 'R') {
539: ($output,$dump)=&r_eval($input,$library,0);
540: } else {
541: $output='Error: unrecognized CAS';
542: }
543: return $output;
544: }
545:
546: sub cas_hashref {
547: my ($system,$input,$library)=@_;
548: if ($system eq 'maxima') {
549: return 'Error: unsupported CAS';
550: } elsif ($system eq 'R') {
551: return &r_eval($input,$library,1);
552: } else {
553: return 'Error: unrecognized CAS';
554: }
555: }
556:
557: #
558: # cas_hashref_entry takes a list of indices and gets the entry in a hash generated by Rreturn.
559: # Call: cas_hashref_entry(Rvalue, index1, index2, ...) where Rvalue is a hash returned by Rreturn.
560: # Rentry will return the first scalar value it encounters (ignoring excess indices).
561: # If an invalid key is given, it returns undef.
562: #
563: sub cas_hashref_entry {
564: return &Rentry(@_);
565: }
566:
567: #
568: # cas_hashref_array takes a list of indices and gets a column array from a hash generated by Rreturn.
569: # Call: cas_hashref_array(Rvalue, index1, index2, ...) where Rvalue is a hash returned by Rreturn.
570: # If an invalid key is given, it returns undef.
571: #
572: sub cas_hashref_array {
573: return &Rarray(@_);
574: }
575:
576: sub tex {
577: if ( $external::target eq "tex" ) {
578: return $_[0];
579: } else {
580: return $_[1];
581: }
582: }
583:
584: sub var_in_tex {
585: if ( $external::target eq "tex" ) {
586: return $_[0];
587: } else {
588: return "";
589: }
590: }
591:
592: sub web {
593: if ( $external::target eq "tex" ) {
594: return $_[1];
595: } else {
596: if ( $external::target eq "web" || $external::target eq "answer") {
597: return $_[2];
598: } else {
599: return $_[0];
600: }
601: }
602: }
603:
604: sub html {
605: if ( $external::target eq "web" ) {
606: return shift;
607: }
608: }
609:
610: sub hinton {
611: return 0;
612: }
613:
614: sub random {
615: my ($start,$end,$step)=@_;
616: if ( ! $hidden::RANDOMINIT ) {
617: if ($external::randomseed == 0) { $external::randomseed=1; }
618: if ($external::randomseed =~/,/) {
619: my ($num1,$num2)=split(/,/,$external::randomseed);
620: &random_set_seed(1,abs($num1));
621: } elsif ($external::randomseed =~/:/) {
622: my ($num1,$num2)=split(/:/,$external::randomseed);
623: &random_set_seed(abs($num1),abs($num2));
624: } else {
625: &random_set_seed(1,int(abs($external::randomseed)));
626: }
627: &math_random_uniform();
628: $hidden::RANDOMINIT=1;
629: }
630: if (!defined($step)) { $step=1; }
631: my $num=1+int(($end-$start)/$step);
632: my $result=$start + int(&math_random_uniform() * $num)*$step;
633: return $result;
634: }
635:
636: sub random_normal {
637: my ($item_cnt,$seed,$av,$std_dev) = @_;
638: my @oldseed=&random_get_seed();
639: my @retArray;
640: &random_set_seed_from_phrase($seed);
641: @retArray=&math_random_normal($item_cnt,$av,$std_dev);
642: &random_set_seed(@oldseed);
643: return @retArray;
644: }
645:
646: sub random_beta {
647: my ($item_cnt,$seed,$aa,$bb) = @_;
648: my @oldseed=&random_get_seed();
649: my @retArray;
650: &random_set_seed_from_phrase($seed);
651: @retArray=&math_random_beta($item_cnt,$aa,$bb);
652: &random_set_seed(@oldseed);
653: return @retArray;
654: }
655:
656: sub random_gamma {
657: my ($item_cnt,$seed,$a,$r) = @_;
658: my @oldseed=&random_get_seed();
659: my @retArray;
660: &random_set_seed_from_phrase($seed);
661: @retArray=&math_random_gamma($item_cnt,$a,$r);
662: &random_set_seed(@oldseed);
663: return @retArray;
664: }
665:
666: sub random_exponential {
667: my ($item_cnt,$seed,$av) = @_;
668: my @oldseed=&random_get_seed();
669: my @retArray;
670: &random_set_seed_from_phrase($seed);
671: @retArray=&math_random_exponential($item_cnt,$av);
672: &random_set_seed(@oldseed);
673: return @retArray;
674: }
675:
676: sub random_poisson {
677: my ($item_cnt,$seed,$mu) = @_;
678: my @oldseed=&random_get_seed();
679: my @retArray;
680: &random_set_seed_from_phrase($seed);
681: @retArray=&math_random_poisson($item_cnt,$mu);
682: &random_set_seed(@oldseed);
683: return @retArray;
684: }
685:
686: sub random_chi {
687: my ($item_cnt,$seed,$df) = @_;
688: my @oldseed=&random_get_seed();
689: my @retArray;
690: &random_set_seed_from_phrase($seed);
691: @retArray=&math_random_chi_square($item_cnt,$df);
692: &random_set_seed(@oldseed);
693: return @retArray;
694: }
695:
696: sub random_noncentral_chi {
697: my ($item_cnt,$seed,$df,$nonc) = @_;
698: my @oldseed=&random_get_seed();
699: my @retArray;
700: &random_set_seed_from_phrase($seed);
701: @retArray=&math_random_noncentral_chi_square($item_cnt,$df,$nonc);
702: &random_set_seed(@oldseed);
703: return @retArray;
704: }
705:
706: sub random_f {
707: my ($item_cnt,$seed,$dfn,$dfd) = @_;
708: my @oldseed=&random_get_seed();
709: my @retArray;
710: &random_set_seed_from_phrase($seed);
711: @retArray=&math_random_f($item_cnt,$dfn,$dfd);
712: &random_set_seed(@oldseed);
713: return @retArray;
714: }
715:
716: sub random_noncentral_f {
717: my ($item_cnt,$seed,$dfn,$dfd,$nonc) = @_;
718: my @oldseed=&random_get_seed();
719: my @retArray;
720: &random_set_seed_from_phrase($seed);
721: @retArray=&math_random_noncentral_f($item_cnt,$dfn,$dfd,$nonc);
722: &random_set_seed(@oldseed);
723: return @retArray;
724: }
725:
726: sub random_multivariate_normal {
727: my ($item_cnt,$seed,$mean,$covar) = @_;
728: my @oldseed=&random_get_seed();
729: &random_set_seed_from_phrase($seed);
730: my @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar);
731: &random_set_seed(@oldseed);
732: return @retArray;
733: }
734:
735: sub random_multinomial {
736: my ($item_cnt,$seed,@p) = @_;
737: my @oldseed=&random_get_seed();
738: my @retArray;
739: &random_set_seed_from_phrase($seed);
740: my @retArray=&math_random_multinomial($item_cnt,@p);
741: &random_set_seed(@oldseed);
742: return @retArray;
743: }
744:
745: sub random_permutation {
746: my ($seed,@inArray) = @_;
747: my @oldseed=&random_get_seed();
748: my @retArray;
749: &random_set_seed_from_phrase($seed);
750: @retArray=&math_random_permutation(@inArray);
751: &random_set_seed(@oldseed);
752: return @retArray;
753: }
754:
755: sub random_uniform {
756: my ($item_cnt,$seed,$low,$high) = @_;
757: my @oldseed=&random_get_seed();
758: my @retArray;
759: &random_set_seed_from_phrase($seed);
760: @retArray=&math_random_uniform($item_cnt,$low,$high);
761: &random_set_seed(@oldseed);
762: return @retArray;
763: }
764:
765: sub random_uniform_integer {
766: my ($item_cnt,$seed,$low,$high) = @_;
767: my @oldseed=&random_get_seed();
768: my @retArray;
769: &random_set_seed_from_phrase($seed);
770: @retArray=&math_random_uniform_integer($item_cnt,$low,$high);
771: &random_set_seed(@oldseed);
772: return @retArray;
773: }
774:
775: sub random_binomial {
776: my ($item_cnt,$seed,$nt,$p) = @_;
777: my @oldseed=&random_get_seed();
778: my @retArray;
779: &random_set_seed_from_phrase($seed);
780: @retArray=&math_random_binomial($item_cnt,$nt,$p);
781: &random_set_seed(@oldseed);
782: return @retArray;
783: }
784:
785: sub random_negative_binomial {
786: my ($item_cnt,$seed,$ne,$p) = @_;
787: my @oldseed=&random_get_seed();
788: my @retArray;
789: &random_set_seed_from_phrase($seed);
790: @retArray=&math_random_negative_binomial($item_cnt,$ne,$p);
791: &random_set_seed(@oldseed);
792: return @retArray;
793: }
794:
795: sub abs { CORE::abs(shift) }
796: sub sin { CORE::sin(shift) }
797: sub cos { CORE::cos(shift) }
798: sub exp { CORE::exp(shift) }
799: sub int { CORE::int(shift) }
800: sub log { CORE::log(shift) }
801: sub atan2 { CORE::atan2($_[0],$_[1]) }
802: sub sqrt { CORE::sqrt(shift) }
803:
804: sub tan { CORE::sin($_[0]) / CORE::cos($_[0]) }
805: #sub atan { atan2($_[0], 1); }
806: #sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
807: #sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) ); }
808:
809: sub log10 { CORE::log($_[0])/CORE::log(10); }
810:
811: sub factorial {
812: my $input = CORE::int(shift);
813: return "Error - unable to take factorial of an negative number ($input)" if $input < 0;
814: return "Error - factorial result is greater than system limit ($input)" if $input > 170;
815: return 1 if $input == 0;
816: my $result = 1;
817: for (my $i=2; $i<=$input; $i++) { $result *= $i }
818: return $result;
819: }
820:
821: sub sgn {
822: return -1 if $_[0] < 0;
823: return 0 if $_[0] == 0;
824: return 1 if $_[0] > 0;
825: }
826:
827: sub min {
828: my @sorted = sort { $a <=> $b || $a cmp $b } @_;
829: return shift @sorted;
830: }
831:
832: sub max {
833: my @sorted = sort { $a <=> $b || $a cmp $b } @_;
834: return pop @sorted;
835: }
836:
837: sub roundto {
838: my ($input,$n) = @_;
839: return sprintf('%.'.$n.'f',$input);
840: }
841:
842: sub to_string {
843: my ($input,$n) = @_;
844: return sprintf($input) if $n eq "";
845: $n = '.'.$n if $n !~ /^\./;
846: return sprintf('%'.$n,$input) if $n ne "";
847: }
848:
849: sub sub_string {
850: my ($str,$start,$len) = @_;
851: return substr($str,$start-1,$len);
852: }
853:
854: sub pow {return $_[0] ** $_[1]; }
855: sub ceil {return (($_[0]-CORE::int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? (CORE::int($_[0])+ 1) : CORE::int($_[0])); }
856: sub floor {return (($_[0]-CORE::int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? CORE::int($_[0]) : (CORE::int($_[0])-1)); }
857: #sub floor {return int($_[0]); }
858:
859: sub format {
860: my ($value,$fmt)=@_;
861: my ($dollarmode,$commamode,$alwaysperiod,$options);
862: if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; }
863: #if ($options =~ /\$/) { $dollamode=1; }
864: #if ($options =~ /,/) { $commamode=1; }
865: if ($options =~ /\./) { $alwaysperiod=1; }
866: my $result;
867: if ($fmt=~/s$/i) {
868: $result=&format_significant_figures($value,$fmt);
869: } else {
870: $fmt=~s/e/E/g;
871: $result=sprintf('%.'.$fmt,$value);
872: if ($alwaysperiod && $fmt eq '0f') { $result .='.'; }
873: $result=~s/(E[+-]*)0/$1/;
874: }
875: #if ($dollarmode) {$result=&dollarformat($result);}
876: #if ($commamode) {$result=&commaformat($result);}
877: return $result;
878: }
879:
880: sub chemparse {
881: my ($reaction) = @_;
882: my @tokens = split(/(\s\+|\->|<=>|<\-|\.)/,$reaction);
883: my $formula = '';
884: foreach my $token (@tokens) {
885: if ($token eq '->' ) {
886: $formula .= '<m>\ensuremath{\rightarrow}</m> ';
887: next;
888: }
889: if ($token eq '<-' ) {
890: $formula .= '<m>\ensuremath{\leftarrow}</m> ';
891: next;
892: }
893: if ($token eq '<=>') {
894: if ($external::target eq 'web' &&
895: &EXT('request.browser.unicode')) {
896: $formula .= '⇌ ';
897: } else {
898: $formula .= &web('<=> ','<m>\ensuremath{\rightleftharpoons}</m> ',
899: '<=> ');
900: }
901: next;
902: }
903: if ($token eq '.') {
904: $formula =~ s/(\ \;| )$//;
905: $formula .= '·';
906: next;
907: }
908: $token =~ /^\s*([\d|\/]*(?:&frac\d\d)?)(.*)/;
909: $formula .= $1 if ($1 ne '1'); # stoichiometric coefficient
910:
911: my $molecule = $2;
912: # subscripts
913: $molecule =~ s|(?<=[a-zA-Z\)\]\s])(\d+)|<sub>$1</sub>|g;
914: # superscripts
915: $molecule =~ s|\^(\d*[+\-]*)|<sup>$1</sup>|g;
916: # strip whitespace
917: $molecule =~ s/\s*//g;
918: # forced space
919: $molecule =~ s/_/ /g;
920: $molecule =~ s/-/−/g;
921: $formula .= $molecule.' ';
922: }
923: # get rid of trailing space
924: $formula =~ s/(\ \;| )$//;
925: return &xmlparse($formula);
926: }
927:
928: sub prettyprint {
929: my ($value,$fmt,$target)=@_;
930: my $result;
931: if (!$target) { $target = $external::target; }
932: if ($fmt =~ /chem/i) { return(&chemparse($value)); }
933: my ($dollarmode,$commamode,$alwaysperiod,$options);
934: if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; }
935: if ($options =~ /\$/) { $dollarmode=1; }
936: if ($options =~ /,/) { $commamode=1; }
937: if ($options =~ /\./) { $alwaysperiod=1; }
938: if ($fmt=~/s$/i) {
939: $value=&format_significant_figures($value,$fmt);
940: } elsif ($fmt) {
941: $value=sprintf('%.'.$fmt,$value);
942: }
943: if ($alwaysperiod && $fmt eq '0f') {
944: if ($target eq 'tex') {
945: $value .='\\ensuremath{.}';
946: } else {
947: $value .='.';
948: }
949: }
950: if ($value =~ /([0-9\.\-\+]+)E([0-9\-\+]+)/i ) {
951: my $frac=$1;
952: if ($dollarmode) { $frac=&dollarformat($frac); }
953: if ($commamode) { $frac=&commaformat($frac); }
954: my $exponent=$2;
955: $exponent=~s/^\+0*//;
956: $exponent=~s/^-0*/-/;
957: $exponent=~s/^-0*/-/;
958: if ($exponent eq '-') { undef($exponent); }
959: if ($exponent) {
960: if ($target eq 'web') {
961: $result=$frac.'×10<sup>'.$exponent.'</sup>';
962: } elsif ($target eq 'tex') {
963: $result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
964: } else {
965: $result=$value;
966: }
967: } else {
968: $result=$frac;
969: }
970: } else {
971: $result=$value;
972: if ($dollarmode) { $result=&dollarformat($result,$target); }
973: elsif ($commamode) { $result=&commaformat($result,$target); }
974: }
975: return $result;
976: }
977:
978: sub commaformat {
979: my ($number,$target) = @_;
980: if ($number =~ /\./) {
981: while ($number =~ /([^0-9]*)([0-9]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*)$/) {
982: $number = $1.$2.','.$3.$4;
983: }
984: } else {
985: while ($number =~ /^([^0-9]*)([0-9]+)([^,][^,][^,])([,0-9]*)$/) {
986: $number = $1.$2.','.$3.$4;
987: }
988: }
989: return $number;
990: }
991:
992: sub dollarformat {
993: my ($number,$target) = @_;
994: if (!$target) { $target = $external::target; }
995: $number=&commaformat($number,$target);
996: if ($target eq 'tex') {
997: $number='\$'.$number; #' stupid emacs
998: } else {
999: $number='$'.$number; #' stupid emacs
1000: }
1001: return $number;
1002: }
1003:
1004: # format of form ns or nS where n is an integer
1005: sub format_significant_figures {
1006: my ($number,$format) = @_;
1007: return '0' if ($number == 0);
1008: # extract number of significant figures needed
1009: my ($sig) = ($format =~ /(\d+)s/i);
1010: # arbitrary choice - suggestions ?? or throw error message?
1011: $sig = 3 if ($sig eq '');
1012: # save the minus sign
1013: my $sign = ($number < 0) ? '-' : '';
1014: $number = abs($number);
1015: # needed to correct for a number greater than 1 (or
1016: my $power = ($number < 1) ? 0 : 1;
1017: # could round up. Take the integer part of log10.
1018: my $x10 = int(log($number)/log(10));
1019: # find number with values left of decimal pt = # of sign figs.
1020: my $xsig = $number*10**($sig-$x10-$power);
1021: # get just digits left of decimal pt - also rounds off correctly
1022: my $xint = sprintf('%.0f',$xsig);
1023: # save any trailing zero's
1024: my ($zeros) = ($xint =~ /(0+)$/);
1025: # return number to original magnitude
1026: my $numSig = $xint*10**($x10-$sig+$power);
1027: # insert trailing zero's if have decimal point
1028: $numSig =~ s/^(\d+)\.(\d+)(\e?(.*)?)$/$1\.$2$zeros$3/;
1029: # put a decimal pt for number ending with 0 and length = # of sig fig
1030: $numSig.='.' if (length($numSig) == $sig && $numSig =~ /0$/);
1031: if (length($numSig) < $sig) {
1032: $numSig.='.'.substr($zeros,0,($sig-length($numSig)));
1033: }
1034: # return number with sign
1035: return $sign.$numSig;
1036:
1037: }
1038:
1039: sub map {
1040: my ($phrase,$dest,$source)=@_;
1041: my @oldseed=&random_get_seed();
1042: my @seed = &random_seed_from_phrase($phrase);
1043: &random_set_seed(@seed);
1044: my $destct = scalar(@$dest);
1045: if (!$source) {
1046: my @output;
1047: my @idx = &math_random_permuted_index($destct);
1048: my $ctr = 0;
1049: while ($ctr < $destct) {
1050: $output[$ctr] = $$dest[$idx[$ctr]];
1051: $ctr++;
1052: }
1053: &random_set_seed(@oldseed);
1054: return @output;
1055: } else {
1056: my $num = scalar(@$source);
1057: my @idx = &math_random_permuted_index($num);
1058: my $ctr = 0;
1059: my $tot = $num;
1060: $tot = $destct if $destct < $num;
1061: if (ref($$dest[0])) {
1062: while ($ctr < $tot) {
1063: ${$$dest[$ctr]} = $$source[$idx[$ctr]];
1064: $ctr++;
1065: }
1066: } else {
1067: while ($ctr < $tot) {
1068: $$dest[$ctr] = $$source[$idx[$ctr]];
1069: $ctr++;
1070: }
1071: }
1072: }
1073: &random_set_seed(@oldseed);
1074: return '';
1075: }
1076:
1077: sub rmap {
1078: my ($phrase,$dest,$source)=@_;
1079: my @oldseed=&random_get_seed();
1080: my @seed = &random_seed_from_phrase($phrase);
1081: &random_set_seed(@seed);
1082: my $destct = scalar(@$dest);
1083: if (!$source) {
1084: my @idx = &math_random_permuted_index($destct);
1085: my $ctr = 0;
1086: my @r_idx;
1087: while ($ctr < $destct) {
1088: $r_idx[$idx[$ctr]] = $ctr;
1089: $ctr++;
1090: }
1091: my @output;
1092: $ctr = 0;
1093: while ($ctr < $destct) {
1094: $output[$ctr] = $$dest[$r_idx[$ctr]];
1095: $ctr++;
1096: }
1097: &random_set_seed(@oldseed);
1098: return @output;
1099: } else {
1100: my $num = scalar(@$source);
1101: my @idx = &math_random_permuted_index($num);
1102: my $ctr = 0;
1103: my $tot = $num;
1104: $tot = $destct if $destct < $num;
1105: my @r_idx;
1106: while ($ctr < $tot) {
1107: $r_idx[$idx[$ctr]] = $ctr;
1108: $ctr++;
1109: }
1110: $ctr = 0;
1111: if (ref($$dest[0])) {
1112: while ($ctr < $tot) {
1113: ${$$dest[$ctr]} = $$source[$r_idx[$ctr]];
1114: $ctr++;
1115: }
1116: } else {
1117: while ($ctr < $tot) {
1118: $$dest[$ctr] = $$source[$r_idx[$ctr]];
1119: $ctr++;
1120: }
1121: }
1122: }
1123: &random_set_seed(@oldseed);
1124: return '';
1125: }
1126:
1127: sub capa_id { return }
1128:
1129: sub problem { return }
1130:
1131: sub name{
1132: my $fullname = &EXT('environment.lastname').', '.&EXT('environment.firstname').' '.&EXT('environment.middlename');
1133: $fullname = "" if $fullname eq ", ";
1134: $fullname =~ s/\%2d/-/g;
1135: return $fullname;
1136: }
1137:
1138: sub student_number {
1139: my $id = &EXT('environment.id');
1140: $id = '' if $id eq "";
1141: return $id;
1142: }
1143:
1144: sub class {
1145: my $course = &EXT('course.description');
1146: $course = '' if $course eq "";
1147: return $course;
1148: }
1149:
1150: sub classid {
1151: my $courseid = &EXT('request.course.id');
1152: $courseid = '' if $courseid eq "";
1153: return $courseid;
1154: }
1155:
1156: sub firstname {
1157: my $firstname = &EXT('environment.firstname');
1158: $firstname = '' if $firstname eq "";
1159: return $firstname;
1160: }
1161:
1162: sub middlename {
1163: my $middlename = &EXT('environment.middlename');
1164: $middlename = '' if $middlename eq "";
1165: return $middlename;
1166: }
1167:
1168:
1169: sub lastname {
1170: my $lastname = &EXT('environment.lastname');
1171: $lastname = '' if $lastname eq "";
1172: return $lastname;
1173: }
1174:
1175: sub sec {
1176: my $sec = &EXT('request.course.sec');
1177: $sec = '' if $sec eq "";
1178: return $sec;
1179: }
1180:
1181: sub submission {
1182: my ($partid,$responseid,$subnumber)=@_;
1183: my $sub='';
1184: if ($subnumber) { $sub=$subnumber.':'; }
1185: return &EXT('user.resource.'.$sub.'resource.'.$partid.'.'.$responseid.'.submission');
1186: }
1187:
1188: sub currentpart {
1189: return $external::part;
1190: }
1191:
1192: sub eval_time {
1193: my ($timestamp)=@_;
1194: unless ($timestamp) { return ''; }
1195: return &locallocaltime($timestamp);
1196: }
1197:
1198: sub open_date {
1199: my ($partid)=@_;
1200: unless ($partid) { $partid=0; }
1201: return &eval_time(&EXT('resource.'.$partid.'.opendate'));
1202: }
1203:
1204: sub due_date {
1205: my ($partid)=@_;
1206: unless ($partid) { $partid=0; }
1207: return &eval_time(&EXT('resource.'.$partid.'.duedate'));
1208: }
1209:
1210: sub answer_date {
1211: my ($partid)=@_;
1212: unless ($partid) { $partid=0; }
1213: return &eval_time(&EXT('resource.'.$partid.'.answerdate'));
1214: }
1215:
1216: sub open_date_epoch {
1217: my ($partid)=@_;
1218: unless ($partid) { $partid=0; }
1219: return &EXT('resource.'.$partid.'.opendate');
1220: }
1221:
1222: sub due_date_epoch {
1223: my ($partid)=@_;
1224: unless ($partid) { $partid=0; }
1225: return &EXT('resource.'.$partid.'.duedate');
1226: }
1227:
1228: sub answer_date_epoch {
1229: my ($partid)=@_;
1230: unless ($partid) { $partid=0; }
1231: return &EXT('resource.'.$partid.'.answerdate');
1232: }
1233:
1234: sub parameter_setting {
1235: my ($which,$partid)=@_;
1236: unless ($partid) { $partid=0; }
1237: return &EXT('resource.'.$partid.'.'.$which);
1238: }
1239:
1240: sub stored_data {
1241: my ($which,$partid)=@_;
1242: unless ($partid) { $partid=0; }
1243: return &EXT('user.resource.resource.'.$partid.'.'.$which);
1244: }
1245:
1246: sub wrong_bubbles {
1247: my ($correct,$lower,$upper,$step,@given)=@_;
1248: my @array=();
1249: my %hash=();
1250: foreach my $new (@given) {
1251: $hash{$new}=1;
1252: }
1253: my $num=int(¶meter_setting('numbubbles',¤tpart()));
1254: unless ($num) { $num=8; }
1255: if ($num>1) {
1256: for (my $i=0;$i<=500;$i++) {
1257: my $new=&random($lower,$upper,$step);
1258: if ($hash{$new}) { next; }
1259: if (abs($new-$correct)<$step) { next; }
1260: $hash{$new}=1;
1261: @array=keys(%hash);
1262: if ($#array+2>=$num) { last; }
1263: }
1264: }
1265: return @array;
1266: }
1267:
1268: sub array_moments {
1269: my @input=@_;
1270: my (@output,$N);
1271: $N=scalar (@input);
1272: $output[0]=$N;
1273: if ($N <= 1) {
1274: $output[1]=$input[0];
1275: $output[1]="Input array not defined" if ($N == 0);
1276: $output[2]="variance undefined for N<=1";
1277: $output[3]="skewness undefined for N<=1";
1278: $output[4]="kurtosis undefined for N<=1";
1279: return @output;
1280: }
1281: my $sum=0;
1282: foreach my $line (@input) {
1283: $sum+=$line;
1284: }
1285: $output[1] = $sum/$N;
1286: my ($x,$sdev,$var,$skew,$kurt) = 0;
1287: foreach my $line (@input) {
1288: $x=$line-$output[1];
1289: $var+=$x**2;
1290: $skew+=$x**3;
1291: $kurt+=$x**4;
1292: }
1293: $output[2]=$var/($N-1);
1294: $sdev=CORE::sqrt($output[2]);
1295: if ($sdev == 0) {
1296: $output[3]="inf-variance=0";
1297: $output[4]="inf-variance=0";
1298: return @output;
1299: }
1300: $output[3]=$skew/($sdev**3*$N);
1301: $output[4]=$kurt/($sdev**4*$N)-3;
1302: return @output;
1303: }
1304:
1305: sub choose {
1306: my $num = $_[0];
1307: return $_[$num];
1308: }
1309:
1310: #&sum1(1,$x,sub { &sum1($_[0],2*$_[0], sub { fact($_[0])**2 })});
1311: #sub sum1 {
1312: # my ($start,$end,$sub)=@_;
1313: # my $sum=0;
1314: # for (my $i=$start;$i<=$end;$i++) {
1315: # $sum+=&$sub($i);
1316: # }
1317: # return $sum
1318: #}
1319:
1320: #&sum2('a',1,$x,'&sum2(\'b\',$a,2*$a, \'&factorial($b)**2\')');
1321: #sub sum2 {
1322: # my ($varname,$start,$end,$line)=@_;
1323: # my $sum=0;
1324: # for (my $i=$start;$i<=$end;$i++) {
1325: # my $func=sub {
1326: # eval("\$".$varname."=$i");
1327: # eval($line);
1328: # };
1329: # $sum+=&$func($i);
1330: # }
1331: # return $sum
1332: #}
1333:
1334: # expiremental idea
1335: sub proper_path {
1336: my ($path)=@_;
1337: if ( $external::target eq "tex" ) {
1338: return '/home/httpd/html'.$path;
1339: } else {
1340: return $path;
1341: }
1342: }
1343:
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