Subversion-Projekte lars-tiefland.php_share

<?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();

?>