[42] | 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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