1 | <?php // content="text/plain; charset=utf-8" |
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2 | require_once ('jpgraph/jpgraph.php'); |
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3 | require_once ('jpgraph/jpgraph_scatter.php'); |
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4 | require_once ('jpgraph/jpgraph_line.php'); |
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5 | require_once ('jpgraph/jpgraph_utils.inc.php'); |
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6 | |
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7 | // Create some "fake" regression data |
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8 | $datay = array(); |
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9 | $datax = array(); |
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10 | $a= 3.2; |
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11 | $b= 2.5; |
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12 | for($x=0; $x < 20; ++$x) { |
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13 | $datax[$x] = $x; |
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14 | $datay[$x] = $a + $b*$x + rand(-20,20); |
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15 | } |
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16 | |
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17 | $lr = new LinearRegression($datax, $datay); |
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18 | list( $stderr, $corr ) = $lr->GetStat(); |
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19 | list( $xd, $yd ) = $lr->GetY(0,19); |
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20 | |
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21 | // Create the graph |
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22 | $graph = new Graph(300,250); |
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23 | $graph->SetScale('linlin'); |
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24 | |
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25 | // Setup title |
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26 | $graph->title->Set("Linear regression"); |
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27 | $graph->title->SetFont(FF_ARIAL,FS_BOLD,14); |
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28 | |
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29 | $graph->subtitle->Set('(stderr='.sprintf('%.2f',$stderr).', corr='.sprintf('%.2f',$corr).')'); |
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30 | $graph->subtitle->SetFont(FF_ARIAL,FS_NORMAL,12); |
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31 | |
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32 | // make sure that the X-axis is always at the |
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33 | // bottom at the plot and not just at Y=0 which is |
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34 | // the default position |
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35 | $graph->xaxis->SetPos('min'); |
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36 | |
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37 | // Create the scatter plot with some nice colors |
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38 | $sp1 = new ScatterPlot($datay,$datax); |
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39 | $sp1->mark->SetType(MARK_FILLEDCIRCLE); |
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40 | $sp1->mark->SetFillColor("red"); |
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41 | $sp1->SetColor("blue"); |
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42 | $sp1->SetWeight(3); |
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43 | $sp1->mark->SetWidth(4); |
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44 | |
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45 | // Create the regression line |
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46 | $lplot = new LinePlot($yd); |
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47 | $lplot->SetWeight(2); |
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48 | $lplot->SetColor('navy'); |
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49 | |
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50 | // Add the pltos to the line |
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51 | $graph->Add($sp1); |
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52 | $graph->Add($lplot); |
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53 | |
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54 | // ... and stroke |
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55 | $graph->Stroke(); |
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56 | |
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57 | ?> |
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58 | |
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59 | |
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