// Contour plot example 04
require_once 'jpgraph/jpgraph.php';
require_once 'jpgraph/jpgraph_contour.php';
$data = array(array(12, 12, 10, 10, 8, 4), array(10, 10, 8, 14, 10, 3), array(7, 7, 13, 17, 12, 8), array(4, 5, 8, 12, 7, 6), array(10, 8, 7, 8, 10, 4));
// Setup a basic graph context with some generous margins to be able
// to fit the legend
$graph = new Graph(500, 380);
$graph->SetMargin(40, 140, 60, 40);
$graph->title->Set("Example of interpolated contour plot");
$graph->title->SetFont(FF_ARIAL, FS_BOLD, 14);
$graph->title->SetMargin(10);
// For contour plots it is custom to use a box style ofr the axis
$graph->legend->SetPos(0.05, 0.5, 'right', 'center');
$graph->SetScale('intint');
// Setup axis and grids
$graph->SetAxisStyle(AXSTYLE_BOXOUT);
$graph->xgrid->SetLineStyle('dashed');
$graph->xgrid->Show(true);
$graph->ygrid->SetLineStyle('dashed');
$graph->ygrid->Show(true);
// A simple contour plot with 10 isobar lines and flipped Y-coordinates
// Make the data smoother by interpolate the original matrice by a factor of two
// which will make each grid cell half the original size
$cp = new ContourPlot($data, 10, 2);
$cp->UseHighContrastColor(true);
// Display the legend
$cp->ShowLegend();
// Make the isobar lines slightly thicker
$graph->Add($cp);
// ... and send the graph back to the browser
$graph->Stroke();
