57 lines
1.3 KiB
PHP
57 lines
1.3 KiB
PHP
|
<?php
|
||
|
include "../jpgraph.php";
|
||
|
include "../jpgraph_line.php";
|
||
|
include "../jpgraph_scatter.php";
|
||
|
include "../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->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();
|
||
|
|
||
|
?>
|
||
|
|