[Sommaire] [Imprimer]

   1  <?php
   2  include  "../jpgraph.php";
   3  include  "../jpgraph_line.php";
   4  include  "../jpgraph_scatter.php";
   5  include  "../jpgraph_regstat.php";
   6  
   7  // Original data points
   8  $xdata = array(1,3,5,7,9,12,15,17.1);
   9  $ydata = array(5,1,9,6,4,3,19,12);
  10  
  11  // Get the interpolated values by creating
  12  // a new Spline object.
  13  $spline = new Spline($xdata,$ydata);
  14  
  15  // For the new data set we want 40 points to
  16  // get a smooth curve.
  17  list($newx,$newy) = $spline->Get(50);
  18  
  19  // Create the graph
  20  $g = new Graph(300,200);
  21  $g->SetMargin(30,20,40,30);
  22  $g->title->Set("Natural cubic splines");
  23  $g->title->SetFont(FF_ARIAL,FS_NORMAL,12);
  24  $g->subtitle->Set('(Control points shown in red)');
  25  $g->subtitle->SetColor('darkred');
  26  $g->SetMarginColor('lightblue');
  27  
  28  //$g->img->SetAntiAliasing();
  29  
  30  // We need a linlin scale since we provide both
  31  // x and y coordinates for the data points.
  32  $g->SetScale('linlin');
  33  
  34  // We want 1 decimal for the X-label
  35  $g->xaxis->SetLabelFormat('%1.1f');
  36  
  37  // We use a scatterplot to illustrate the original
  38  // contro points.
  39  $splot = new ScatterPlot($ydata,$xdata);
  40  
  41  // 
  42  $splot->mark->SetFillColor('red@0.3');
  43  $splot->mark->SetColor('red@0.5');
  44  
  45  // And a line plot to stroke the smooth curve we got
  46  // from the original control points
  47  $lplot = new LinePlot($newy,$newx);
  48  $lplot->SetColor('navy');
  49  
  50  // Add the plots to the graph and stroke
  51  $g->Add($lplot);
  52  $g->Add($splot);
  53  $g->Stroke();
  54  
  55  ?>
  56