[Sommaire] [Imprimer]

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