Annotation of loncom/homework/default_homework.lcpm, revision 1.46
1.42 albertel 1: # The LearningOnline Network with CAPA
1.1 harris41 2: # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
1.42 albertel 3: #
1.46 ! albertel 4: # $Id: default_homework.lcpm,v 1.45 2002/01/30 17:32:05 albertel Exp $
1.42 albertel 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: #
1.20 harris41 28: #
29: # Guy Albertelli
30: #
31: # 05/25/2001 H. K. Ng
1.24 ng 32: # 05/31/2001 H. K. Ng
1.44 matthew 33: # 12/21/2001 Matthew
1.20 harris41 34: #
1.25 albertel 35: #init some globals
1.38 albertel 36: $hidden::RANDOMINIT=0;
1.22 ng 37: $pi=atan2(1,1)*4;
38: $rad2deg=180.0/$pi;
39: $deg2rad=$pi/180.0;
1.44 matthew 40: $"=' ';
1.3 albertel 41:
1.7 albertel 42: sub caparesponse_check {
1.36 albertel 43: #not properly used yet: calc
44: #not to be used: $ans_fmt
1.39 albertel 45: my ($answer,$type,$tol,$sig,$ans_fmt,$unit,$calc,$samples) =
46: eval $_[1].
47: ';return ($answer,$type,$tol,$sig,$ans_fmt,$unit,$calc,$samples);';
1.36 albertel 48:
1.10 albertel 49: my $tol_type=''; # gets it's value from whether tol has a % or not done
1.19 albertel 50: my $sig_lbound=''; #done
51: my $sig_ubound=''; #done
1.7 albertel 52: my ($response,$expr)=@_;
1.31 albertel 53:
1.32 albertel 54:
1.8 albertel 55: #type's definitons come from capaParser.h
1.31 albertel 56: my $message='';
1.32 albertel 57: #remove leading and trailing whitespace
58: if ($response=~ /^\s|\s$/) {
59: $response=~ s:^\s+|\s+$::g;
60: $message .="Removed ws now :$response:<br />";
61: } else {
62: $message .="no ws in :$response:<br />";
63: }
64:
1.8 albertel 65: if ($type eq '' ) {
1.31 albertel 66: $message .= "Didn't find a type :$type:$expr: defaulting<br />";
1.8 albertel 67: if ( $answer eq ($answer *1.0)) { $type = 2;
68: } else { $type = 3; }
69: } else {
70: if ($type eq 'cs') { $type = 4;
71: } elsif ($type eq 'ci') { $type = 3;
72: } elsif ($type eq 'mc') { $type = 5;
73: } elsif ($type eq 'fml') { $type = 8;
1.9 albertel 74: } elsif ($type eq 'subj') { $type = 7;
1.41 albertel 75: } elsif ($type eq 'float') { $type = 2;
76: } elsif ($type eq 'int') { $type = 1;
1.9 albertel 77: } else { return "ERROR: Unknown type of answer: $type" }
1.8 albertel 78: }
79:
1.39 albertel 80: my $points;
81: my $id_list;
82: #formula type setup the sample points
83: if ($type eq '8') {
84: ($id_list,$points)=split(/@/,$samples);
85: $message.="Found :$points: points<br />";
86: }
1.10 albertel 87: if ($tol eq '') {
88: $tol=0.0;
89: $tol_type=1; #TOL_ABSOLUTE
90: } else {
91: if ($tol =~ /%$/) {
1.12 albertel 92: chop $tol;
1.10 albertel 93: $tol_type=2; #TOL_PERCENTAGE
94: } else {
95: $tol_type=1; #TOL_ABSOLUTE
96: }
97: }
1.12 albertel 98:
99: if ($sig eq '') {
100: $sig_lbound = 0; #SIG_LB_DEFAULT
101: $sig_ubound =15; #SIG_UB_DEFAULT
102: } else {
103: ($sig_lbound,$sig_ubound) = split /,/,$sig;
1.45 albertel 104: if (!$sig_lbound) {
105: $sig_lbound = 0; #SIG_LB_DEFAULT
106: $sig_ubound =15; #SIG_UB_DEFAULT
107: }
108: if (!$sig_ubound) { $sig_ubound=$sig_lbound; }
1.12 albertel 109: }
1.7 albertel 110: my $result = &caparesponse_capa_check_answer($response,$answer,$type,
1.10 albertel 111: $tol_type,$tol,
1.7 albertel 112: $sig_lbound,$sig_ubound,
1.39 albertel 113: $ans_fmt,$unit,$calc,$id_list,
114: $points,$external::randomseed);
1.9 albertel 115:
116: if ($result == '1') { $result='EXACT_ANS'; }
117: elsif ($result == '2') { $result='APPROX_ANS'; }
118: elsif ($result == '3') { $result='SIG_FAIL'; }
119: elsif ($result == '4') { $result='UNIT_FAIL'; }
120: elsif ($result == '5') { $result='NO_UNIT'; }
121: elsif ($result == '6') { $result='UNIT_OK'; }
122: elsif ($result == '7') { $result='INCORRECT'; }
123: elsif ($result == '8') { $result='UNIT_NOTNEEDED'; }
124: elsif ($result == '9') { $result='ANS_CNT_NOT_MATCH'; }
125: elsif ($result =='10') { $result='SUB_RECORDED'; }
126: elsif ($result =='11') { $result='BAD_FORMULA'; }
127: elsif ($result =='12') { $result='WANTED_NUMERIC'; }
1.13 albertel 128: else {$result = "ERROR: Unknown Result:$result:$@:";}
1.9 albertel 129:
1.36 albertel 130: return "$result:<br />Error $error:<br />Answer $answer:<br />Response $response:<br /> type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|<br />$message$expr";
1.14 albertel 131: }
132:
1.37 albertel 133: sub get_array_args {
134: my ($expr,$arg)=@_;
1.30 albertel 135: # do these first, because who knows what varname the instructor might have used
136: # but it probably isn't $CAPARESPONSE_CHECK_LIST_answer
1.37 albertel 137: my $CAPARESPONSE_CHECK_LIST_answer = eval $expr.';return $'.$arg; #'
1.40 albertel 138: my $GET_ARRAY_ARGS_result;
139: my @GET_ARRAY_ARGS_list;
1.39 albertel 140: if ($CAPARESPONSE_CHECK_LIST_answer =~ /^\s*[\$\@]/) {
1.40 albertel 141: (@GET_ARRAY_ARGS_list) = eval $CAPARESPONSE_CHECK_LIST_answer;
1.39 albertel 142: }
1.40 albertel 143: $GET_ARRAY_ARGS_result.="error:$@:<br />";
1.31 albertel 144: # if the eval fails just use what is in the answer exactly
1.40 albertel 145: if (!defined(@GET_ARRAY_ARGS_list) || !defined($GET_ARRAY_ARGS_list[0])) {
146: $GET_ARRAY_ARGS_result.="list zero is undefined<br />";
147: $GET_ARRAY_ARGS_list[0]=$CAPARESPONSE_CHECK_LIST_answer;
1.31 albertel 148: }
1.40 albertel 149: return $GET_ARRAY_ARGS_result,@GET_ARRAY_ARGS_list;
1.37 albertel 150: }
151:
152: sub caparesponse_check_list {
153: my ($response,$expr)=@_;
1.40 albertel 154: my $result;
155: my ($result,@list) = &get_array_args($expr,'answer');
1.15 albertel 156: my $aresult='';
1.14 albertel 157: my $current_answer;
1.39 albertel 158: my $answers=join(':',@list);
159: $result.="Got response :$answers:<br />";
1.31 albertel 160: my @responselist;
1.32 albertel 161: my $type =eval $expr.';return $answer;';
1.31 albertel 162: if ($type ne '' && $#list > 0) {
163: (@responselist)=split /,/,$response;
164: } else {
165: (@responselist)=($response);
166: }
1.15 albertel 167: my $unit='';
1.31 albertel 168: $result.="Initial final response :$responselist['-1']:<br />";
169: if ($type eq '') {
170: #for numerical problems split off the unit
171: if ( $responselist['-1']=~ /(.*[^\s])\s+([^\s]+)/ ) {
172: $responselist['-1']=$1;
173: $unit=$2;
174: }
1.15 albertel 175: }
1.31 albertel 176: $result.="Final final response :$responselist['-1']:<br />";
177: $result.=":$#list: answers<br />";
1.14 albertel 178: $unit=~s/\s//;
179: my $i=0;
180: my $awards='';
181: for ($i=0; $i<@list;$i++) {
1.31 albertel 182: $result.="trying answer :$list[$i]:<br />";
1.19 albertel 183: if ($unit eq '') {
184: $aresult=&caparesponse_check($responselist[$i],
1.31 albertel 185: $expr.';my $answer=\''.$list[$i].'\';');
1.19 albertel 186: } else {
187: $aresult=&caparesponse_check($responselist[$i]." $unit",
1.31 albertel 188: $expr.';my $answer=\''.$list[$i].'\';');
1.19 albertel 189: }
1.15 albertel 190: my ($temp)=split /:/, $aresult;
1.14 albertel 191: $awards.="$temp,";
1.15 albertel 192: $result.=$aresult;
1.14 albertel 193: }
194: chop $awards;
1.17 albertel 195: return "$awards:<br />$result";
1.7 albertel 196: }
197:
1.4 albertel 198: sub tex {
199: if ( $external::target eq "tex" ) {
200: return @_[0];
201: } else {
202: return @_[1];
203: }
204: }
205:
1.24 ng 206: sub var_in_tex {
207: if ( $external::target eq "tex" ) {
208: return @_[0];
209: } else {
210: return "";
211: }
212: }
213:
1.4 albertel 214: sub web {
215: if ( $external::target eq "tex" ) {
216: return @_[1];
217: } else {
1.43 albertel 218: if ( $external::target eq "web" || $external::target eq "answer") {
1.26 ng 219: return @_[2];
220: } else {
1.4 albertel 221: return @_[0];
222: }
223: }
224: }
225:
1.24 ng 226: sub html {
227: if ( $external::target eq "web" ) {
1.26 ng 228: return shift;
1.24 ng 229: }
230: }
231:
1.4 albertel 232: sub problem {
1.11 albertel 233: return '1';
1.4 albertel 234: }
235:
1.1 harris41 236: sub hinton {
237: return 0;
238: }
239:
240: sub random {
241: my ($start,$end,$step)=@_;
1.38 albertel 242: if ( ! $hidden::RANDOMINIT ) {
243: srand($external::randomseed);
244: $hidden::RANDOMINIT=1;
245: }
1.45 albertel 246: if (!defined($step)) { $step=1; }
1.1 harris41 247: my $num=1+int(($end-$start)/$step);
248: my $result=$start + int(rand() * $num)*$step;
249: return $result;
250: }
251:
1.26 ng 252: sub random_normal {
253: my ($item_cnt,$seed,$av,$std_dev) = @_;
254: my @retArray;
255: &random_set_seed_from_phrase($seed);
256: @retArray=&math_random_normal($item_cnt,$av,$std_dev);
257: return @retArray;
258: }
259:
260: sub random_beta {
261: my ($item_cnt,$seed,$aa,$bb) = @_;
262: my @retArray;
263: &random_set_seed_from_phrase($seed);
264: @retArray=&math_random_beta($item_cnt,$aa,$bb);
265: return @retArray;
266: }
267:
268: sub random_gamma {
269: my ($item_cnt,$seed,$a,$r) = @_;
270: my @retArray;
271: &random_set_seed_from_phrase($seed);
272: @retArray=&math_random_gamma($item_cnt,$a,$r);
273: return @retArray;
274: }
275:
276: sub random_exponential {
277: my ($item_cnt,$seed,$av) = @_;
278: my @retArray;
279: &random_set_seed_from_phrase($seed);
280: @retArray=&math_random_exponential($item_cnt,$av);
281: return @retArray;
282: }
283:
284: sub random_poisson {
285: my ($item_cnt,$seed,$mu) = @_;
286: my @retArray;
287: &random_set_seed_from_phrase($seed);
288: @retArray=&math_random_poisson($item_cnt,$mu);
289: return @retArray;
290: }
291:
292: sub random_chi {
293: my ($item_cnt,$seed,$df) = @_;
294: my @retArray;
295: &random_set_seed_from_phrase($seed);
296: @retArray=&math_random_chi_square($item_cnt,$df);
297: return @retArray;
298: }
299:
300: sub random_noncentral_chi {
301: my ($item_cnt,$seed,$df,$nonc) = @_;
302: my @retArray;
303: &random_set_seed_from_phrase($seed);
304: @retArray=&math_random_noncentral_chi_square($item_cnt,$df,$nonc);
305: return @retArray;
306: }
307:
308: sub random_f {
309: my ($item_cnt,$seed,$dfn,$dfd) = @_;
310: my @retArray;
311: &random_set_seed_from_phrase($seed);
312: @retArray=&math_random_f($item_cnt,$dfn,$dfd);
313: return @retArray;
314: }
315:
316: sub random_noncentral_f {
317: my ($item_cnt,$seed,$dfn,$dfd,$nonc) = @_;
318: my @retArray;
319: &random_set_seed_from_phrase($seed);
320: @retArray=&math_random_noncentral_f($item_cnt,$dfn,$dfd,$nonc);
321: return @retArray;
322: }
323:
324: sub random_multivariate_normal {
1.33 ng 325: my ($item_cnt,$seed,$mean,$covar) = @_;
1.26 ng 326: &random_set_seed_from_phrase($seed);
1.33 ng 327: @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar);
1.26 ng 328: return @retArray;
329: }
330:
331: sub random_multinomial {
332: my ($item_cnt,$seed,@p) = @_;
333: my @retArray;
334: &random_set_seed_from_phrase($seed);
335: @retArray=&math_random_multinomial($item_cnt,@p);
336: return @retArray;
337: }
338:
339: sub random_permutation {
340: my ($seed,@inArray) = @_;
341: my @retArray;
342: &random_set_seed_from_phrase($seed);
343: @retArray=&math_random_permutation(@inArray);
344: return @retArray;
345: }
346:
347: sub random_uniform {
348: my ($item_cnt,$seed,$low,$high) = @_;
349: my @retArray;
350: &random_set_seed_from_phrase($seed);
351: @retArray=&math_random_uniform($item_cnt,$low,$high);
352: return @retArray;
353: }
354:
355: sub random_uniform_integer {
356: my ($item_cnt,$seed,$low,$high) = @_;
357: my @retArray;
358: &random_set_seed_from_phrase($seed);
359: @retArray=&math_random_uniform_integer($item_cnt,$low,$high);
360: return @retArray;
361: }
362:
363: sub random_binomial {
364: my ($item_cnt,$seed,$nt,$p) = @_;
365: my @retArray;
366: &random_set_seed_from_phrase($seed);
367: @retArray=&math_random_binomial($item_cnt,$nt,$p);
368: return @retArray;
369: }
370:
371: sub random_negative_binomial {
372: my ($item_cnt,$seed,$ne,$p) = @_;
373: my @retArray;
374: &random_set_seed_from_phrase($seed);
375: @retArray=&math_random_negative_binomial($item_cnt,$ne,$p);
376: return @retArray;
377: }
378:
1.23 ng 379: sub abs { abs(shift) }
380: sub sin { sin(shift) }
381: sub cos { cos(shift) }
382: sub exp { exp(shift) }
383: sub int { int(shift) }
384: sub log { log(shift) }
385: sub atan2 { atan2($_[0],$_[1]) }
386: sub sqrt { sqrt(shift) }
387:
1.1 harris41 388: sub tan { sin($_[0]) / cos($_[0]) }
1.21 harris41 389: #sub atan { atan2($_[0], 1); }
390: #sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
391: #sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) ); }
1.22 ng 392:
1.18 albertel 393: sub log10 { log($_[0])/log(10); }
1.22 ng 394:
1.20 harris41 395: sub factorial {
396: my $input = int(shift);
397: return "Error - unable to take factorial of an negative number ($input)" if $input < 0;
398: return "Error - factorial result is greater than system limit ($input)" if $input > 170;
399: return 1 if $input == 0;
400: my $result = 1;
401: for (my $i=2; $i<=$input; $i++) { $result *= $i }
402: return $result;
403: }
404:
405: sub sgn {
406: return -1 if $_[0] < 0;
407: return 0 if $_[0] == 0;
408: return 1 if $_[0] > 0;
409: }
410:
411: sub min {
412: my @sorted = sort { $a <=> $b || $a cmp $b } @_;
413: return shift @sorted;
414: }
415:
416: sub max {
417: my @sorted = sort { $a <=> $b || $a cmp $b } @_;
418: return pop @sorted;
419: }
1.1 harris41 420:
1.20 harris41 421: sub roundto {
422: my ($input,$n) = @_;
423: return sprintf('%.'.$n.'f',$input);
424: }
425:
426: sub to_string {
427: my ($input,$n) = @_;
1.26 ng 428: return sprintf($input) if $n eq "";
429: $n = '.'.$n if $n !~ /^\./;
1.20 harris41 430: return sprintf('%'.$n,$input) if $n ne "";
431: }
432:
433: sub sub_string {
434: my ($str,$start,$len) = @_;
435: return substr($str,$start-1,$len);
436: }
1.1 harris41 437:
438: sub pow {return $_[0] ** $_[1]; }
1.27 ng 439: sub ceil {return (($_[0]-int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? (int($_[0])+ 1) : int($_[0])); }
440: sub floor {return (($_[0]-int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? int($_[0]) : (int($_[0])-1)); }
441: #sub floor {return int($_[0]); }
1.1 harris41 442:
1.2 albertel 443: sub format {
444: my ($value,$fmt)=@_;
1.11 albertel 445: return sprintf('%.'.$fmt,$value);
1.46 ! albertel 446: }
! 447:
! 448: sub prettyprint {
! 449: my ($value,$fmt)=@_;
! 450: my $result;
! 451: if ($fmt) { $value=sprintf('%.'.$fmt,$value); }
! 452: if ($value =~ /([0-9\.\-\+]+)E([0-9\-\+]+)/ ) {
! 453: my $frac=$1;
! 454: my $exponent=$2;
! 455: $exponent=~s/^\+0*//;
! 456: if ($external::target eq 'web') {
! 457: $result=$frac.'×10<sup>'.$exponent.'</sup>';
! 458: } elsif ($external::target eq 'tex') {
! 459: $result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
! 460: } else {
! 461: $result=$value;
! 462: }
! 463: } else {
! 464: $result=$value;
! 465: }
! 466: return $result;
1.2 albertel 467: }
1.5 albertel 468:
469: sub map {
1.27 ng 470: my ($phrase,$dest,$source)=@_;
471: my @seed = &random_seed_from_phrase($phrase);
472: &random_set_seed(@seed);
473: my $destct = scalar(@$dest);
1.28 ng 474: if (!$source) {
475: my @output;
476: my @idx = &math_random_permuted_index($destct);
477: my $ctr = 0;
478: while ($ctr < $destct) {
479: $output[$ctr] = $$dest[$idx[$ctr]];
1.27 ng 480: $ctr++;
1.28 ng 481: }
482: return @output;
1.27 ng 483: } else {
1.28 ng 484: my $num = scalar(@$source);
485: my @idx = &math_random_permuted_index($num);
486: my $ctr = 0;
487: my $tot = $num;
488: $tot = $destct if $destct < $num;
489: if (ref($$dest[0])) {
490: while ($ctr < $tot) {
491: ${$$dest[$ctr]} = $$source[$idx[$ctr]];
492: $ctr++;
493: }
494: } else {
495: while ($ctr < $tot) {
496: $$dest[$ctr] = $$source[$idx[$ctr]];
497: $ctr++;
498: }
499: }
1.27 ng 500: }
501: }
502:
503: sub rmap {
504: my ($phrase,$dest,$source)=@_;
505: my @seed = &random_seed_from_phrase($phrase);
506: &random_set_seed(@seed);
507: my $destct = scalar(@$dest);
1.28 ng 508: if (!$source) {
509: my @idx = &math_random_permuted_index($destct);
510: my $ctr = 0;
511: my @r_idx;
512: while ($ctr < $destct) {
513: $r_idx[$idx[$ctr]] = $ctr;
514: $ctr++;
515: }
516: my @output;
517: $ctr = 0;
518: while ($ctr < $destct) {
519: $output[$ctr] = $$dest[$r_idx[$ctr]];
1.27 ng 520: $ctr++;
1.28 ng 521: }
522: return @output;
1.27 ng 523: } else {
1.28 ng 524: my $num = scalar(@$source);
525: my @idx = &math_random_permuted_index($num);
526: my $ctr = 0;
527: my $tot = $num;
528: $tot = $destct if $destct < $num;
529: my @r_idx;
1.27 ng 530: while ($ctr < $tot) {
1.28 ng 531: $r_idx[$idx[$ctr]] = $ctr;
1.27 ng 532: $ctr++;
1.28 ng 533: }
534: $ctr = 0;
535: if (ref($$dest[0])) {
536: while ($ctr < $tot) {
537: ${$$dest[$ctr]} = $$source[$r_idx[$ctr]];
538: $ctr++;
539: }
540: } else {
541: while ($ctr < $tot) {
542: $$dest[$ctr] = $$source[$r_idx[$ctr]];
543: $ctr++;
544: }
545: }
1.6 albertel 546: }
1.5 albertel 547: }
1.22 ng 548:
1.23 ng 549: sub capa_id { return }
550:
551: sub problem { return }
552:
1.22 ng 553: sub name{
554: my $fullname = &EXT('environment.lastname').', '.&EXT('environment.firstname').' '.&EXT('environment.middlename');
555: $fullname = "" if $fullname eq ", ";
1.26 ng 556: $fullname =~ s/\%2d/-/g;
1.22 ng 557: return $fullname;
558: }
559:
560: sub student_number {
561: my $id = &EXT('environment.id');
562: $id = '' if $id eq "";
563: return $id;
564: }
565:
566: sub class {
567: my $course = &EXT('course.description');
568: $course = '' if $course eq "";
569: return $course;
570: }
571:
572: sub sec {
573: my $sec = &EXT('request.course.sec');
1.23 ng 574: $sec = '' if $sec eq "";
1.22 ng 575: return $sec;
576: }
577:
1.23 ng 578: sub open_date {
579: my @dc = split(/\s+/,localtime(&EXT('resource.0.opendate')));
1.24 ng 580: return '' if ($dc[0] eq "Wed" and $dc[2] == 31 and $dc[4] == 1969);
581: my @hm = split(/:/,$dc[3]);
582: my $ampm = " am";
583: if ($hm[0] > 12) {
584: $hm[0]-=12;
585: $ampm = " pm";
586: }
587: return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$hm[0].':'.$hm[1].$ampm;
1.23 ng 588: }
589:
590: sub due_date {
591: my @dc = split(/\s+/,localtime(&EXT('resource.0.duedate')));
1.24 ng 592: return '' if ($dc[0] eq "Wed" and $dc[2] == 31 and $dc[4] == 1969);
593: my @hm = split(/:/,$dc[3]);
594: my $ampm = " am";
595: if ($hm[0] > 12) {
596: $hm[0]-=12;
597: $ampm = " pm";
598: }
599: return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$hm[0].':'.$hm[1].$ampm;
600: # return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$dc[3];
1.23 ng 601: }
602:
603: sub answer_date {
604: my @dc = split(/\s+/,localtime(&EXT('resource.0.answerdate')));
1.24 ng 605: return '' if ($dc[0] eq "Wed" and $dc[2] == 31 and $dc[4] == 1969);
606: my @hm = split(/:/,$dc[3]);
607: my $ampm = " am";
608: if ($hm[0] > 12) {
609: $hm[0]-=12;
610: $ampm = " pm";
611: }
612: return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$hm[0].':'.$hm[1].$ampm;
613: # return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$dc[3];
614: }
615:
616: sub array_moments {
617: my @input=@_;
618: my (@output,$N);
619: $N=scalar (@input);
620: $output[0]=$N;
621: if ($N <= 1) {
622: $output[1]=$input[0];
1.28 ng 623: $output[1]="Input array not defined" if ($N == 0);
1.24 ng 624: $output[2]="variance undefined for N<=1";
625: $output[3]="skewness undefined for N<=1";
626: $output[4]="kurtosis undefined for N<=1";
627: return @output;
628: }
629: my $sum=0;
630: foreach my $line (@input) {
631: $sum+=$line;
632: }
633: $output[1] = $sum/$N;
634: my ($x,$sdev,$var,$skew,$kurt) = 0;
635: foreach my $line (@input) {
636: $x=$line-$output[1];
637: $var+=$x**2;
638: $skew+=$x**3;
639: $kurt+=$x**4;
640: }
641: $output[2]=$var/($N-1);
642: $sdev=sqrt($output[2]);
643: if ($sdev == 0) {
644: $output[3]="inf-variance=0";
645: $output[4]="inf-variance=0";
646: return @output;
647: }
648: $output[3]=$skew/($sdev**3*$N);
649: $output[4]=$kurt/($sdev**4*$N)-3;
650: return @output;
651: }
1.5 albertel 652:
653: sub choose {
654: my $num = $_[0];
655: return $_[$num];
656: }
1.23 ng 657:
658:
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