mod/survey/graph.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * This file is responsible for producing the graph for survey reports
  20  *
  21  * @package   mod_survey
  22  * @copyright 2021 Sujith Haridasan <sujith@moodle.com>
  23  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 require_once("../../config.php");
  27 require_once("$CFG->libdir/graphlib.php");
  28 require_once("lib.php");
  29
  30 $id = required_param('id', PARAM_INT);    // Course Module ID.
  31 $type = required_param('type', PARAM_FILE);  // Graph Type.
  32 $group = optional_param('group', 0, PARAM_INT);  // Group ID.
  33 $sid = optional_param('sid', false, PARAM_INT);  // Student ID.
  34 $qid = optional_param('qid', 0, PARAM_INT);  // Group ID.
  35
  36 $url = new moodle_url('/mod/survey/graph.php', array('id' => $id, 'type' => $type));
  37 if ($group !== 0) {
  38     $url->param('group', $group);
  39 }
  40 if ($sid !== false) {
  41     $url->param('sid', $sid);
  42 }
  43 if ($qid !== 0) {
  44     $url->param('qid', $qid);
  45 }
  46 $PAGE->set_url($url);
  47
  48 if (!$cm = get_coursemodule_from_id('survey', $id)) {
  49     throw new \moodle_exception('invalidcoursemodule');
  50 }
  51
  52 if (!$course = $DB->get_record("course", array("id" => $cm->course))) {
  53     throw new \moodle_exception('coursemisconf');
  54 }
  55
  56 if ($sid) {
  57     if (!$user = $DB->get_record("user", array("id" => $sid))) {
  58         throw new \moodle_exception('invaliduserid');
  59     }
  60 }
  61
  62 require_login($course, false, $cm);
  63
  64 $groupmode = groups_get_activity_groupmode($cm);   // Groups are being used.
  65 $context = context_module::instance($cm->id);
  66
  67 if (!has_capability('mod/survey:readresponses', $context)) {
  68     if ($type != "student.png" or $sid != $USER->id) {
  69         throw new \moodle_exception('nopermissiontoshow');
  70     } else if ($groupmode and !groups_is_member($group)) {
  71         throw new \moodle_exception('nopermissiontoshow');
  72     }
  73 }
  74
  75 if (!$survey = $DB->get_record("survey", array("id" => $cm->instance))) {
  76     throw new \moodle_exception('invalidsurveyid', 'survey');
  77 }
  78
  79 // Check to see if groups are being used in this survey.
  80 if ($group) {
  81     $users = get_users_by_capability($context, 'mod/survey:participate', '', '', '', '', $group, null, false);
  82 } else if (!empty($cm->groupingid)) {
  83     $groups = groups_get_all_groups($courseid, 0, $cm->groupingid);
  84     $groups = array_keys($groups);
  85     $users = get_users_by_capability($context, 'mod/survey:participate', '', '', '', '', $groups, null, false);
  86 } else {
  87     $users = get_users_by_capability($context, 'mod/survey:participate', '', '', '', '', '', null, false);
  88     $group = false;
  89 }
  90
  91 $stractual = get_string("actual", "survey");
  92 $stractualclass = get_string("actualclass", "survey");
  93
  94 $strpreferred = get_string("preferred", "survey");
  95 $strpreferredclass = get_string("preferredclass", "survey");
  96
  97 if ($sid || isset($user)) {
  98     $stractualstudent = get_string("actualstudent", "survey", fullname($user));
  99     $strpreferredstudent = get_string("preferredstudent", "survey", fullname($user));
 100 }
 101
 102 $virtualscales = false; // Set default value for case clauses.
 103
 104 switch ($type) {
 105
 106     case "question.png":
 107
 108         $question = $DB->get_record("survey_questions", array("id" => $qid));
 109         $question->text = wordwrap(get_string($question->text, "survey"), SURVEY_QLENGTH_WRAP);
 110         $question->options = get_string($question->options, "survey");
 111
 112         $options = explode(",", $question->options);
 113
 114         foreach ($options as $key => $unused) {
 115             $buckets1[$key] = 0;
 116             $buckets2[$key] = 0;
 117         }
 118
 119         if ($aaa = $DB->get_records('survey_answers', array('survey' => $cm->instance, 'question' => $qid))) {
 120             foreach ($aaa as $aa) {
 121                 if (!$group or isset($users[$aa->userid])) {
 122                     if ($a1 = $aa->answer1) {
 123                         $buckets1[$a1 - 1]++;
 124                     }
 125                     if ($a2 = $aa->answer2) {
 126                         $buckets2[$a2 - 1]++;
 127                     }
 128                 }
 129             }
 130         }
 131
 132         $maxbuckets1 = max($buckets1);
 133         $maxbuckets2 = max($buckets2);
 134         $maxbuckets = ($maxbuckets1 > $maxbuckets2) ? $maxbuckets1 : $maxbuckets2;
 135
 136         $graph = new graph($SURVEY_GWIDTH, $SURVEY_GHEIGHT);
 137         $graph->parameter['title'] = "$question->text";
 138
 139         $graph->x_data = $options;
 140
 141         $graph->y_data['answers1'] = $buckets1;
 142         $graph->y_format['answers1'] = array('colour' => 'ltblue', 'bar' => 'fill', 'legend' => $stractual, 'bar_size' => 0.4);
 143         $graph->y_data['answers2'] = $buckets2;
 144         $graph->y_format['answers2'] = array('colour' => 'ltorange', 'bar' => 'fill', 'legend' => $strpreferred, 'bar_size' => 0.2);
 145
 146         $graph->parameter['legend'] = 'outside-top';
 147         $graph->parameter['legend_border'] = 'black';
 148         $graph->parameter['legend_offset'] = 4;
 149
 150         if (($maxbuckets1 > 0.0) && ($maxbuckets2 > 0.0)) {
 151             $graph->y_order = array('answers1', 'answers2');
 152         } else if ($maxbuckets1 > 0.0) {
 153             $graph->y_order = array('answers1');
 154         } else {
 155             $graph->y_order = array('answers2');
 156         }
 157
 158         $graph->parameter['y_axis_gridlines'] = $maxbuckets + 1;
 159         $graph->parameter['y_resolution_left'] = 1;
 160         $graph->parameter['y_decimal_left'] = 0;
 161         $graph->parameter['x_axis_angle'] = 20;
 162         $graph->parameter['shadow'] = 'none';
 163
 164         $graph->y_tick_labels = null;
 165         $graph->offset_relation = null;
 166
 167         $graph->draw_stack();
 168
 169         break;
 170
 171     case "multiquestion.png":
 172
 173         $question = $DB->get_record("survey_questions", array("id" => $qid));
 174         $question->text = get_string($question->text, "survey");
 175         $question->options = get_string($question->options, "survey");
 176
 177         $options = explode(",", $question->options);
 178         $questionorder = explode(",", $question->multi);
 179
 180         $qqq = $DB->get_records_list("survey_questions", "id", explode(',', $question->multi));
 181
 182         foreach ($questionorder as $i => $val) {
 183             $names[$i] = get_string($qqq["$val"]->shorttext, "survey");
 184             $buckets1[$i] = 0;
 185             $buckets2[$i] = 0;
 186             $count1[$i] = 0;
 187             $count2[$i] = 0;
 188             $indexof[$val] = $i;
 189             $stdev1[$i] = 0;
 190             $stdev2[$i] = 0;
 191         }
 192
 193         $aaa = $DB->get_records_select("survey_answers", "((survey = ?) AND (question in ($question->multi)))",
 194                 array($cm->instance));
 195
 196         if ($aaa) {
 197             foreach ($aaa as $a) {
 198                 if (!$group or isset($users[$a->userid])) {
 199                     $index = $indexof[$a->question];
 200                     if ($a->answer1) {
 201                         $buckets1[$index] += $a->answer1;
 202                         $count1[$index]++;
 203                     }
 204                     if ($a->answer2) {
 205                         $buckets2[$index] += $a->answer2;
 206                         $count2[$index]++;
 207                     }
 208                 }
 209             }
 210         }
 211
 212         foreach ($questionorder as $i => $val) {
 213             if ($count1[$i]) {
 214                 $buckets1[$i] = (float) $buckets1[$i] / (float) $count1[$i];
 215             }
 216             if ($count2[$i]) {
 217                 $buckets2[$i] = (float) $buckets2[$i] / (float) $count2[$i];
 218             }
 219         }
 220
 221         if ($aaa) {
 222             foreach ($aaa as $a) {
 223                 if (!$group or isset($users[$a->userid])) {
 224                     $index = $indexof[$a->question];
 225                     if ($a->answer1) {
 226                         $difference = (float) ($a->answer1 - $buckets1[$index]);
 227                         $stdev1[$index] += ($difference * $difference);
 228                     }
 229                     if ($a->answer2) {
 230                         $difference = (float) ($a->answer2 - $buckets2[$index]);
 231                         $stdev2[$index] += ($difference * $difference);
 232                     }
 233                 }
 234             }
 235         }
 236
 237         foreach ($questionorder as $i => $val) {
 238             if ($count1[$i]) {
 239                 $stdev1[$i] = sqrt((float) $stdev1[$i] / ((float) $count1[$i]));
 240             }
 241             if ($count2[$i]) {
 242                 $stdev2[$i] = sqrt((float) $stdev2[$i] / ((float) $count2[$i]));
 243             }
 244             $buckets1[$i] = $buckets1[$i] - 1;
 245             $buckets2[$i] = $buckets2[$i] - 1;
 246         }
 247
 248         $maxbuckets1 = max($buckets1);
 249         $maxbuckets2 = max($buckets2);
 250
 251         $graph = new graph($SURVEY_GWIDTH, $SURVEY_GHEIGHT);
 252         $graph->parameter['title'] = "$question->text";
 253
 254         $graph->x_data = $names;
 255         $graph->y_data['answers1'] = $buckets1;
 256         $graph->y_format['answers1'] = array('colour' => 'ltblue', 'line' => 'line', 'point' => 'square',
 257                 'shadow_offset' => 4, 'legend' => $stractual);
 258         $graph->y_data['answers2'] = $buckets2;
 259         $graph->y_format['answers2'] = array('colour' => 'ltorange', 'line' => 'line', 'point' => 'square',
 260                 'shadow_offset' => 4, 'legend' => $strpreferred);
 261         $graph->y_data['stdev1'] = $stdev1;
 262         $graph->y_format['stdev1'] = array('colour' => 'ltltblue', 'bar' => 'fill',
 263                 'shadow_offset' => '4', 'legend' => 'none', 'bar_size' => 0.3);
 264         $graph->y_data['stdev2'] = $stdev2;
 265         $graph->y_format['stdev2'] = array('colour' => 'ltltorange', 'bar' => 'fill',
 266                 'shadow_offset' => '4', 'legend' => 'none', 'bar_size' => 0.2);
 267         $graph->offset_relation['stdev1'] = 'answers1';
 268         $graph->offset_relation['stdev2'] = 'answers2';
 269
 270         $graph->parameter['bar_size'] = 0.15;
 271
 272         $graph->parameter['legend'] = 'outside-top';
 273         $graph->parameter['legend_border'] = 'black';
 274         $graph->parameter['legend_offset'] = 4;
 275
 276         $graph->y_tick_labels = $options;
 277
 278         if (($maxbuckets1 > 0.0) && ($maxbuckets2 > 0.0)) {
 279             $graph->y_order = array('stdev1', 'answers1', 'stdev2', 'answers2');
 280         } else if ($maxbuckets1 > 0.0) {
 281             $graph->y_order = array('stdev1', 'answers1');
 282         } else {
 283             $graph->y_order = array('stdev2', 'answers2');
 284         }
 285
 286         $graph->parameter['y_max_left'] = count($options) - 1;
 287         $graph->parameter['y_axis_gridlines'] = count($options);
 288         $graph->parameter['y_resolution_left'] = 1;
 289         $graph->parameter['y_decimal_left'] = 1;
 290         $graph->parameter['x_axis_angle'] = 20;
 291
 292         $graph->draw();
 293
 294         break;
 295
 296     case "overall.png":
 297
 298         $qqq = $DB->get_records_list("survey_questions", "id", explode(',', $survey->questions));
 299
 300         foreach ($qqq as $key => $qq) {
 301             if ($qq->multi) {
 302                 $qqq[$key]->text = get_string($qq->text, "survey");
 303                 $qqq[$key]->options = get_string($qq->options, "survey");
 304                 if ($qq->type < 0) {
 305                     $virtualscales = true;
 306                 }
 307             }
 308         }
 309         foreach ($qqq as $qq) {         // If any virtual, then use JUST virtual, else use JUST nonvirtual.
 310             if ($qq->multi) {
 311                 if ($virtualscales && $qq->type < 0) {
 312                     $question[] = $qq;
 313                 } else if (!$virtualscales && $qq->type > 0) {
 314                     $question[] = $qq;
 315                 }
 316             }
 317         }
 318         $numquestions = count($question);
 319
 320         $options = explode(",", $question[0]->options);
 321         $numoptions = count($options);
 322
 323         for ($i = 0; $i < $numquestions; $i++) {
 324             $names[$i] = $question[$i]->text;
 325             $buckets1[$i] = 0.0;
 326             $buckets2[$i] = 0.0;
 327             $stdev1[$i] = 0.0;
 328             $stdev2[$i] = 0.0;
 329             $count1[$i] = 0;
 330             $count2[$i] = 0;
 331             $subquestions = $question[$i]->multi;   // Otherwise next line doesn't work.
 332             $aaa = $DB->get_records_select("survey_answers", "((survey = ?) AND (question in ($subquestions)))",
 333                     array($cm->instance));
 334
 335             if ($aaa) {
 336                 foreach ($aaa as $a) {
 337                     if (!$group or isset($users[$a->userid])) {
 338                         if ($a->answer1) {
 339                             $buckets1[$i] += $a->answer1;
 340                             $count1[$i]++;
 341                         }
 342                         if ($a->answer2) {
 343                             $buckets2[$i] += $a->answer2;
 344                             $count2[$i]++;
 345                         }
 346                     }
 347                 }
 348             }
 349
 350             if ($count1[$i]) {
 351                 $buckets1[$i] = (float) $buckets1[$i] / (float) $count1[$i];
 352             }
 353             if ($count2[$i]) {
 354                 $buckets2[$i] = (float) $buckets2[$i] / (float) $count2[$i];
 355             }
 356
 357             // Calculate the standard devaiations.
 358             if ($aaa) {
 359                 foreach ($aaa as $a) {
 360                     if (!$group or isset($users[$a->userid])) {
 361                         if ($a->answer1) {
 362                             $difference = (float) ($a->answer1 - $buckets1[$i]);
 363                             $stdev1[$i] += ($difference * $difference);
 364                         }
 365                         if ($a->answer2) {
 366                             $difference = (float) ($a->answer2 - $buckets2[$i]);
 367                             $stdev2[$i] += ($difference * $difference);
 368                         }
 369                     }
 370                 }
 371             }
 372
 373             if ($count1[$i]) {
 374                 $stdev1[$i] = sqrt((float) $stdev1[$i] / ((float) $count1[$i]));
 375             }
 376             if ($count2[$i]) {
 377                 $stdev2[$i] = sqrt((float) $stdev2[$i] / ((float) $count2[$i]));
 378             }
 379
 380             $buckets1[$i] = $buckets1[$i] - 1;         // Hack because there should not be ANY 0 values in the data.
 381             $buckets2[$i] = $buckets2[$i] - 1;
 382
 383         }
 384
 385         $maxbuckets1 = max($buckets1);
 386         $maxbuckets2 = max($buckets2);
 387
 388         $graph = new graph($SURVEY_GWIDTH, $SURVEY_GHEIGHT);
 389         $graph->parameter['title'] = strip_tags(format_string($survey->name, true));
 390
 391         $graph->x_data = $names;
 392
 393         $graph->y_data['answers1'] = $buckets1;
 394         $graph->y_format['answers1'] = array('colour' => 'ltblue', 'line' => 'line', 'point' => 'square',
 395                 'shadow_offset' => 4, 'legend' => $stractual);
 396         $graph->y_data['answers2'] = $buckets2;
 397         $graph->y_format['answers2'] = array('colour' => 'ltorange', 'line' => 'line', 'point' => 'square',
 398                 'shadow_offset' => 4, 'legend' => $strpreferred);
 399
 400         $graph->y_data['stdev1'] = $stdev1;
 401         $graph->y_format['stdev1'] = array('colour' => 'ltltblue', 'bar' => 'fill',
 402                 'shadow_offset' => '4', 'legend' => 'none', 'bar_size' => 0.3);
 403         $graph->y_data['stdev2'] = $stdev2;
 404         $graph->y_format['stdev2'] = array('colour' => 'ltltorange', 'bar' => 'fill',
 405                 'shadow_offset' => '4', 'legend' => 'none', 'bar_size' => 0.2);
 406         $graph->offset_relation['stdev1'] = 'answers1';
 407         $graph->offset_relation['stdev2'] = 'answers2';
 408
 409         $graph->parameter['legend'] = 'outside-top';
 410         $graph->parameter['legend_border'] = 'black';
 411         $graph->parameter['legend_offset'] = 4;
 412
 413         $graph->y_tick_labels = $options;
 414
 415         if (($maxbuckets1 > 0.0) && ($maxbuckets2 > 0.0)) {
 416             $graph->y_order = array('stdev1', 'answers1', 'stdev2', 'answers2');
 417         } else if ($maxbuckets1 > 0.0) {
 418             $graph->y_order = array('stdev1', 'answers1');
 419         } else {
 420             $graph->y_order = array('stdev2', 'answers2');
 421         }
 422
 423         $graph->parameter['y_max_left'] = $numoptions - 1;
 424         $graph->parameter['y_axis_gridlines'] = $numoptions;
 425         $graph->parameter['y_resolution_left'] = 1;
 426         $graph->parameter['y_decimal_left'] = 1;
 427         $graph->parameter['x_axis_angle'] = 0;
 428         $graph->parameter['x_inner_padding'] = 6;
 429
 430         $graph->draw();
 431
 432         break;
 433
 434     case "student.png":
 435
 436         $qqq = $DB->get_records_list("survey_questions", "id", explode(',', $survey->questions));
 437
 438         foreach ($qqq as $key => $qq) {
 439             if ($qq->multi) {
 440                 $qqq[$key]->text = get_string($qq->text, "survey");
 441                 $qqq[$key]->options = get_string($qq->options, "survey");
 442                 if ($qq->type < 0) {
 443                     $virtualscales = true;
 444                 }
 445             }
 446         }
 447         foreach ($qqq as $qq) {         // If any virtual, then use JUST virtual, else use JUST nonvirtual.
 448             if ($qq->multi) {
 449                 if ($virtualscales && $qq->type < 0) {
 450                     $question[] = $qq;
 451                 } else if (!$virtualscales && $qq->type > 0) {
 452                     $question[] = $qq;
 453                 }
 454             }
 455         }
 456         $numquestions = count($question);
 457
 458         $options = explode(",", $question[0]->options);
 459         $numoptions = count($options);
 460
 461         for ($i = 0; $i < $numquestions; $i++) {
 462             $names[$i] = $question[$i]->text;
 463             $buckets1[$i] = 0.0;
 464             $buckets2[$i] = 0.0;
 465             $count1[$i] = 0;
 466             $count2[$i] = 0;
 467             $studbuckets1[$i] = 0.0;
 468             $studbuckets2[$i] = 0.0;
 469             $studcount1[$i] = 0;
 470             $studcount2[$i] = 0;
 471             $stdev1[$i] = 0.0;
 472             $stdev2[$i] = 0.0;
 473
 474             $subquestions = $question[$i]->multi;   // Otherwise next line doesn't work.
 475             $aaa = $DB->get_records_select("survey_answers", "((survey = ?) AND (question in ($subquestions)))",
 476                     array($cm->instance));
 477
 478             if ($aaa) {
 479                 foreach ($aaa as $a) {
 480                     if (!$group or isset($users[$a->userid])) {
 481                         if ($a->userid == $sid) {
 482                             if ($a->answer1) {
 483                                 $studbuckets1[$i] += $a->answer1;
 484                                 $studcount1[$i]++;
 485                             }
 486                             if ($a->answer2) {
 487                                 $studbuckets2[$i] += $a->answer2;
 488                                 $studcount2[$i]++;
 489                             }
 490                         }
 491                         if ($a->answer1) {
 492                             $buckets1[$i] += $a->answer1;
 493                             $count1[$i]++;
 494                         }
 495                         if ($a->answer2) {
 496                             $buckets2[$i] += $a->answer2;
 497                             $count2[$i]++;
 498                         }
 499                     }
 500                 }
 501             }
 502
 503             if ($count1[$i]) {
 504                 $buckets1[$i] = (float) $buckets1[$i] / (float) $count1[$i];
 505             }
 506             if ($count2[$i]) {
 507                 $buckets2[$i] = (float) $buckets2[$i] / (float) $count2[$i];
 508             }
 509             if ($studcount1[$i]) {
 510                 $studbuckets1[$i] = (float) $studbuckets1[$i] / (float) $studcount1[$i];
 511             }
 512             if ($studcount2[$i]) {
 513                 $studbuckets2[$i] = (float) $studbuckets2[$i] / (float) $studcount2[$i];
 514             }
 515
 516             // Calculate the standard devaiations.
 517             foreach ($aaa as $a) {
 518                 if (!$group or isset($users[$a->userid])) {
 519                     if ($a->answer1) {
 520                         $difference = (float) ($a->answer1 - $buckets1[$i]);
 521                         $stdev1[$i] += ($difference * $difference);
 522                     }
 523                     if ($a->answer2) {
 524                         $difference = (float) ($a->answer2 - $buckets2[$i]);
 525                         $stdev2[$i] += ($difference * $difference);
 526                     }
 527                 }
 528             }
 529
 530             if ($count1[$i]) {
 531                 $stdev1[$i] = sqrt((float) $stdev1[$i] / ((float) $count1[$i]));
 532             }
 533             if ($count2[$i]) {
 534                 $stdev2[$i] = sqrt((float) $stdev2[$i] / ((float) $count2[$i]));
 535             }
 536
 537             $buckets1[$i] = $buckets1[$i] - 1;         // Hack because there should not be ANY 0 values in the data.
 538             $buckets2[$i] = $buckets2[$i] - 1;
 539             $studbuckets1[$i] = $studbuckets1[$i] - 1;
 540             $studbuckets2[$i] = $studbuckets2[$i] - 1;
 541
 542         }
 543
 544         $maxbuckets1 = max($buckets1);
 545         $maxbuckets2 = max($buckets2);
 546
 547         $graph = new graph($SURVEY_GWIDTH, $SURVEY_GHEIGHT);
 548         $graph->parameter['title'] = strip_tags(format_string($survey->name, true));
 549
 550         $graph->x_data = $names;
 551
 552         $graph->y_data['answers1'] = $buckets1;
 553         $graph->y_format['answers1'] = array('colour' => 'ltblue', 'line' => 'line', 'point' => 'square',
 554                 'shadow_offset' => 0.1, 'legend' => $stractualclass);
 555         $graph->y_data['answers2'] = $buckets2;
 556         $graph->y_format['answers2'] = array('colour' => 'ltorange', 'line' => 'line', 'point' => 'square',
 557                 'shadow_offset' => 0.1, 'legend' => $strpreferredclass);
 558         $graph->y_data['studanswers1'] = $studbuckets1;
 559         $graph->y_format['studanswers1'] = array('colour' => 'blue', 'line' => 'line', 'point' => 'square',
 560                 'shadow_offset' => 4, 'legend' => $stractualstudent);
 561         $graph->y_data['studanswers2'] = $studbuckets2;
 562         $graph->y_format['studanswers2'] = array('colour' => 'orange', 'line' => 'line', 'point' => 'square',
 563                 'shadow_offset' => 4, 'legend' => $strpreferredstudent);
 564         $graph->y_data['stdev1'] = $stdev1;
 565         $graph->y_format['stdev1'] = array('colour' => 'ltltblue', 'bar' => 'fill',
 566                 'shadow_offset' => 0.1, 'legend' => 'none', 'bar_size' => 0.3);
 567         $graph->y_data['stdev2'] = $stdev2;
 568         $graph->y_format['stdev2'] = array('colour' => 'ltltorange', 'bar' => 'fill',
 569                 'shadow_offset' => 0.1, 'legend' => 'none', 'bar_size' => 0.2);
 570         $graph->offset_relation['stdev1'] = 'answers1';
 571         $graph->offset_relation['stdev2'] = 'answers2';
 572
 573         $graph->y_tick_labels = $options;
 574
 575         $graph->parameter['bar_size'] = 0.15;
 576
 577         $graph->parameter['legend'] = 'outside-top';
 578         $graph->parameter['legend_border'] = 'black';
 579         $graph->parameter['legend_offset'] = 4;
 580
 581         if (($maxbuckets1 > 0.0) && ($maxbuckets2 > 0.0)) {
 582             $graph->y_order = array('stdev1', 'stdev2', 'answers1', 'answers2', 'studanswers1', 'studanswers2');
 583         } else if ($maxbuckets1 > 0.0) {
 584             $graph->y_order = array('stdev1', 'answers1', 'studanswers1');
 585         } else {
 586             $graph->y_order = array('stdev2', 'answers2', 'studanswers2');
 587         }
 588
 589         $graph->parameter['y_max_left'] = $numoptions - 1;
 590         $graph->parameter['y_axis_gridlines'] = $numoptions;
 591         $graph->parameter['y_resolution_left'] = 1;
 592         $graph->parameter['y_decimal_left'] = 1;
 593         $graph->parameter['x_axis_angle'] = 20;
 594
 595         $graph->draw();
 596         break;
 597
 598     case "studentmultiquestion.png":
 599
 600         $question = $DB->get_record("survey_questions", array("id" => $qid));
 601         $question->text = get_string($question->text, "survey");
 602         $question->options = get_string($question->options, "survey");
 603
 604         $options = explode(",", $question->options);
 605         $questionorder = explode(",", $question->multi);
 606
 607         $qqq = $DB->get_records_list("survey_questions", "id", explode(',', $question->multi));
 608
 609         foreach ($questionorder as $i => $val) {
 610             $names[$i] = get_string($qqq[$val]->shorttext, "survey");
 611             $buckets1[$i] = 0;
 612             $buckets2[$i] = 0;
 613             $count1[$i] = 0;
 614             $count2[$i] = 0;
 615             $indexof[$val] = $i;
 616             $studbuckets1[$i] = 0.0;
 617             $studbuckets2[$i] = 0.0;
 618             $studcount1[$i] = 0;
 619             $studcount2[$i] = 0;
 620             $stdev1[$i] = 0.0;
 621             $stdev2[$i] = 0.0;
 622         }
 623
 624         $aaa = $DB->get_records_select("survey_answers", "((survey = ?) AND (question in ($question->multi)))",
 625                 array($cm->instance));
 626
 627         if ($aaa) {
 628             foreach ($aaa as $a) {
 629                 if (!$group or isset($users[$a->userid])) {
 630                     $index = $indexof[$a->question];
 631                     if ($a->userid == $sid) {
 632                         if ($a->answer1) {
 633                             $studbuckets1[$index] += $a->answer1;
 634                             $studcount1[$index]++;
 635                         }
 636                         if ($a->answer2) {
 637                             $studbuckets2[$index] += $a->answer2;
 638                             $studcount2[$index]++;
 639                         }
 640                     }
 641                     if ($a->answer1) {
 642                         $buckets1[$index] += $a->answer1;
 643                         $count1[$index]++;
 644                     }
 645                     if ($a->answer2) {
 646                         $buckets2[$index] += $a->answer2;
 647                         $count2[$index]++;
 648                     }
 649                 }
 650             }
 651         }
 652
 653         foreach ($questionorder as $i => $val) {
 654             if ($count1[$i]) {
 655                 $buckets1[$i] = (float) $buckets1[$i] / (float) $count1[$i];
 656             }
 657             if ($count2[$i]) {
 658                 $buckets2[$i] = (float) $buckets2[$i] / (float) $count2[$i];
 659             }
 660             if ($studcount1[$i]) {
 661                 $studbuckets1[$i] = (float) $studbuckets1[$i] / (float) $studcount1[$i];
 662             }
 663             if ($studcount2[$i]) {
 664                 $studbuckets2[$i] = (float) $studbuckets2[$i] / (float) $studcount2[$i];
 665             }
 666         }
 667
 668         foreach ($aaa as $a) {
 669             if (!$group or isset($users[$a->userid])) {
 670                 $index = $indexof[$a->question];
 671                 if ($a->answer1) {
 672                     $difference = (float) ($a->answer1 - $buckets1[$index]);
 673                     $stdev1[$index] += ($difference * $difference);
 674                 }
 675                 if ($a->answer2) {
 676                     $difference = (float) ($a->answer2 - $buckets2[$index]);
 677                     $stdev2[$index] += ($difference * $difference);
 678                 }
 679             }
 680         }
 681
 682         foreach ($questionorder as $i => $val) {
 683             if ($count1[$i]) {
 684                 $stdev1[$i] = sqrt((float) $stdev1[$i] / ((float) $count1[$i]));
 685             }
 686             if ($count2[$i]) {
 687                 $stdev2[$i] = sqrt((float) $stdev2[$i] / ((float) $count2[$i]));
 688             }
 689             $buckets1[$i] = $buckets1[$i] - 1;         // Hack because there should not be ANY 0 values in the data.
 690             $buckets2[$i] = $buckets2[$i] - 1;
 691             $studbuckets1[$i] = $studbuckets1[$i] - 1;
 692             $studbuckets2[$i] = $studbuckets2[$i] - 1;
 693         }
 694
 695         $maxbuckets1 = max($buckets1);
 696         $maxbuckets2 = max($buckets2);
 697
 698         $graph = new graph($SURVEY_GWIDTH, $SURVEY_GHEIGHT);
 699         $graph->parameter['title'] = "$question->text";
 700
 701         $graph->x_data = $names;
 702         $graph->y_data['answers1'] = $buckets1;
 703         $graph->y_format['answers1'] = array('colour' => 'ltblue', 'line' => 'line', 'point' => 'square',
 704                 'shadow_offset' => 0.1, 'legend' => $stractualclass);
 705         $graph->y_data['answers2'] = $buckets2;
 706         $graph->y_format['answers2'] = array('colour' => 'ltorange', 'line' => 'line', 'point' => 'square',
 707                 'shadow_offset' => 0.1, 'legend' => $strpreferredclass);
 708         $graph->y_data['studanswers1'] = $studbuckets1;
 709         $graph->y_format['studanswers1'] = array('colour' => 'blue', 'line' => 'line', 'point' => 'square',
 710                 'shadow_offset' => 4, 'legend' => $stractualstudent);
 711         $graph->y_data['studanswers2'] = $studbuckets2;
 712         $graph->y_format['studanswers2'] = array('colour' => 'orange', 'line' => 'line', 'point' => 'square',
 713                 'shadow_offset' => 4, 'legend' => $strpreferredstudent);
 714         $graph->y_data['stdev1'] = $stdev1;
 715         $graph->y_format['stdev1'] = array('colour' => 'ltltblue', 'bar' => 'fill',
 716                 'shadow_offset' => 0.1, 'legend' => 'none', 'bar_size' => 0.3);
 717         $graph->y_data['stdev2'] = $stdev2;
 718         $graph->y_format['stdev2'] = array('colour' => 'ltltorange', 'bar' => 'fill',
 719                 'shadow_offset' => 0.1, 'legend' => 'none', 'bar_size' => 0.2);
 720         $graph->offset_relation['stdev1'] = 'answers1';
 721         $graph->offset_relation['stdev2'] = 'answers2';
 722
 723         $graph->parameter['bar_size'] = 0.15;
 724
 725         $graph->parameter['legend'] = 'outside-top';
 726         $graph->parameter['legend_border'] = 'black';
 727         $graph->parameter['legend_offset'] = 4;
 728
 729         $graph->y_tick_labels = $options;
 730
 731         if (($maxbuckets1 > 0.0) && ($maxbuckets2 > 0.0)) {
 732             $graph->y_order = array('stdev1', 'stdev2', 'answers1', 'answers2', 'studanswers1', 'studanswers2');
 733         } else if ($maxbuckets1 > 0.0) {
 734             $graph->y_order = array('stdev1', 'answers1', 'studanswers1');
 735         } else {
 736             $graph->y_order = array('stdev2', 'answers2', 'studanswers2');
 737         }
 738
 739         $graph->parameter['y_max_left'] = count($options) - 1;
 740         $graph->parameter['y_axis_gridlines'] = count($options);
 741         $graph->parameter['y_resolution_left'] = 1;
 742         $graph->parameter['y_decimal_left'] = 1;
 743         $graph->parameter['x_axis_angle'] = 20;
 744
 745         $graph->draw();
 746
 747         break;
 748
 749     default:
 750         break;
 751 }
 752
 753 exit;