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site/jpgraph/Examples/splineex1.php 1.45 KB
8ec98c9f   Guillaume   MAJ
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  <?php // content="text/plain; charset=utf-8"
  require_once ('jpgraph/jpgraph.php');
  require_once ('jpgraph/jpgraph_line.php');
  require_once ('jpgraph/jpgraph_scatter.php');
  require_once ('jpgraph/jpgraph_regstat.php');
  
  // Original data points
  $xdata = array(1,3,5,7,9,12,15,17.1);
  $ydata = array(5,1,9,6,4,3,19,12);
  
  // Get the interpolated values by creating
  // a new Spline object.
  $spline = new Spline($xdata,$ydata);
  
  // For the new data set we want 40 points to
  // get a smooth curve.
  list($newx,$newy) = $spline->Get(50);
  
  // Create the graph
  $g = new Graph(300,200);
  $g->clearTheme();
  $g->SetMargin(30,20,40,30);
  $g->title->Set("Natural cubic splines");
  $g->title->SetFont(FF_ARIAL,FS_NORMAL,12);
  $g->subtitle->Set('(Control points shown in red)');
  $g->subtitle->SetColor('darkred');
  $g->SetMarginColor('lightblue');
  
  //$g->img->SetAntiAliasing();
  
  // We need a linlin scale since we provide both
  // x and y coordinates for the data points.
  $g->SetScale('linlin');
  
  // We want 1 decimal for the X-label
  $g->xaxis->SetLabelFormat('%1.1f');
  
  // We use a scatterplot to illustrate the original
  // contro points.
  $splot = new ScatterPlot($ydata,$xdata);
  
  //
  $splot->mark->SetFillColor('red@0.3');
  $splot->mark->SetColor('red@0.5');
  
  // And a line plot to stroke the smooth curve we got
  // from the original control points
  $lplot = new LinePlot($newy,$newx);
  $lplot->SetColor('navy');
  
  // Add the plots to the graph and stroke
  $g->Add($lplot);
  $g->Add($splot);
  $g->Stroke();
  
  ?>