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