1 | <?php // content="text/plain; charset=utf-8" |
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2 | // Example on how to treat and format timestamp as human readable labels |
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3 | require_once ('jpgraph/jpgraph.php'); |
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4 | require_once ('jpgraph/jpgraph_line.php'); |
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5 | |
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6 | // Number of "fake" data points |
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7 | DEFINE('NDATAPOINTS',500); |
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8 | |
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9 | // Assume data points are sample every 10th second |
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10 | DEFINE('SAMPLERATE',10); |
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11 | |
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12 | // Callback formatting function for the X-scale to convert timestamps |
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13 | // to hour and minutes. |
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14 | function TimeCallback($aVal) { |
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15 | return Date('H:i', $aVal); |
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16 | } |
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17 | |
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18 | // Get start time |
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19 | $start = time(); |
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20 | // Set the start time to be on the closest minute just before the "start" timestamp |
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21 | $adjstart = floor($start / 60); |
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22 | |
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23 | // Create a data set in range (20,100) and X-positions |
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24 | // We also apply a simple low pass filter on the data to make it less |
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25 | // random and a little smoother |
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26 | $data = array(); |
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27 | $xdata = array(); |
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28 | $data[0] = rand(20,100); |
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29 | $xdata[0] = $adjstart; |
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30 | for( $i=1; $i < NDATAPOINTS; ++$i ) { |
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31 | $data[$i] = rand(20,100)*0.2 + $data[$i-1]*0.8; |
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32 | $xdata[$i] = $adjstart + $i * SAMPLERATE; |
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33 | } |
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34 | |
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35 | // Assume that the data points represents data that is sampled every 10s |
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36 | // when determing the end value on the scale. We also add some extra |
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37 | // length to end on an even label tick. |
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38 | $adjend = $adjstart + (NDATAPOINTS+10)*10; |
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39 | |
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40 | $graph = new Graph(500,250); |
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41 | $graph->SetMargin(40,20,30,50); |
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42 | |
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43 | // Now specify the X-scale explicit but let the Y-scale be auto-scaled |
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44 | $graph->SetScale("intlin",0,0,$adjstart,$adjend); |
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45 | $graph->title->Set("Example on TimeStamp Callback"); |
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46 | |
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47 | // Setup the callback and adjust the angle of the labels |
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48 | $graph->xaxis->SetLabelFormatCallback('TimeCallback'); |
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49 | $graph->xaxis->SetLabelAngle(90); |
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50 | |
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51 | // Set the labels every 5min (i.e. 300seconds) and minor ticks every minute |
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52 | $graph->xaxis->scale->ticks->Set(300,60); |
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53 | |
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54 | $line = new LinePlot($data,$xdata); |
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55 | $line->SetColor('lightblue'); |
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56 | $graph->Add($line); |
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57 | |
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58 | $graph->Stroke(); |
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59 | ?> |
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