mod/survey/graph.php

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