mod/survey/graph.php

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