Viewing file: timestampex01.php (1.77 KB) -rw-r--r-- Select action/file-type: (+) | (+) | (+) | Code (+) | Session (+) | (+) | SDB (+) | (+) | (+) | (+) | (+) | (+) |
<?php // Example on how to treat and format timestamp as human readable labels require_once("../jpgraph.php"); require_once("../jpgraph_line.php");
// Number of "fake" data points DEFINE('NDATAPOINTS',500);
// Assume data points are sample every 10th second DEFINE('SAMPLERATE',10);
// Callback formatting function for the X-scale to convert timestamps // to hour and minutes. function TimeCallback($aVal) { return Date('H:i', $aVal); }
// Get start time $start = time(); // Set the start time to be on the closest minute just before the "start" timestamp $adjstart = floor($start / 60);
// Create a data set in range (20,100) and X-positions // We also apply a simple low pass filter on the data to make it less // random and a little smoother $data = array(); $xdata = array(); $data[0] = rand(20,100); $xdata[0] = $adjstart; for( $i=1; $i < NDATAPOINTS; ++$i ) { $data[$i] = rand(20,100)*0.2 + $data[$i-1]*0.8; $xdata[$i] = $adjstart + $i * SAMPLERATE; }
// Assume that the data points represents data that is sampled every 10s // when determing the end value on the scale. We also add some extra // length to end on an even label tick. $adjend = $adjstart + (NDATAPOINTS+10)*10;
$graph = new Graph(500,250); $graph->SetMargin(40,20,30,50);
// Now specify the X-scale explicit but let the Y-scale be auto-scaled $graph->SetScale("intlin",0,0,$adjstart,$adjend); $graph->title->Set("Example on TimeStamp Callback");
// Setup the callback and adjust the angle of the labels $graph->xaxis->SetLabelFormatCallback('TimeCallback'); $graph->xaxis->SetLabelAngle(90);
// Set the labels every 5min (i.e. 300seconds) and minor ticks every minute $graph->xaxis->scale->ticks->Set(300,60);
$line = new LinePlot($data,$xdata); $line->SetColor('lightblue'); $graph->Add($line);
$graph->Stroke(); ?>
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