ChartDirector 7.0 (PHP Edition)

Contour Color Scale


      

This example demonstrates using various color scales for contour charts.

ChartDirector supports two ways to configure the color scale:

This example includes 4 charts to demonstrate both of the above methods.

Source Code Listing

[File: phpdemo/contourcolor.php]
<?php
require_once("../lib/phpchartdir.php");

function createChart($viewer, $chartIndex)
{
    # The x and y coordinates of the grid
    $dataX = array(-4, -3, -2, -1, 0, 1, 2, 3, 4);
    $dataY = array(-4, -3, -2, -1, 0, 1, 2, 3, 4);

    # Use random numbers for the z values on the XY grid
    $r = new RanSeries(99);
    $dataZ = $r->get2DSeries(count($dataX), count($dataY), -0.9, 0.9);

    # Create a XYChart object of size 420 x 360 pixels
    $c = new XYChart(420, 360);

    # Set the plotarea at (30, 25) and of size 300 x 300 pixels. Use semi-transparent grey
    # (0xdd000000) horizontal and vertical grid lines
    $c->setPlotArea(30, 25, 300, 300, -1, -1, -1, 0xdd000000, -1);

    # Set the x-axis and y-axis scale
    $c->xAxis->setLinearScale(-4, 4, 1);
    $c->yAxis->setLinearScale(-4, 4, 1);

    # Add a contour layer using the given data
    $layer = $c->addContourLayer($dataX, $dataY, $dataZ);

    # Enable contour label by setting its style to black (000000) 8pt default bold font
    $layer->setContourLabelStyle("bold", 8, 0x000000);

    # Set the label to display the value in a CDML block with semi-transparent white (4FFFFFFF)
    # background and 2 pixels left/right margin and 1 pixel top/bottom margin
    $layer->setContourLabelFormat("<*block,bgcolor=4FFFFFFF,margin=2 2 1 1*>{value}");

    # Move the grid lines in front of the contour layer
    $c->getPlotArea()->moveGridBefore($layer);

    # Add a color axis (the legend) in which the top left corner is anchored at (350, 25). Set the
    # length to 400 300 and the labels on the right side.
    $cAxis = $layer->setColorAxis(350, 25, TopLeft, 300, Right);

    if ($chartIndex == 1) {
        # Speicify a color gradient as a list of colors, and use it in the color axis.
        $colorGradient = array(0x0044cc, 0xffffff, 0x00aa00);
        $cAxis->setColorGradient(false, $colorGradient);
    } else if ($chartIndex == 2) {
        # Specify the color scale to use in the color axis
        $colorScale = array(-1.0, 0x1a9850, -0.75, 0x66bd63, -0.5, 0xa6d96a, -0.25, 0xd9ef8b, 0,
            0xfee08b, 0.25, 0xfdae61, 0.5, 0xf46d43, 0.75, 0xd73027, 1);
        $cAxis->setColorScale($colorScale);
    } else if ($chartIndex == 3) {
        # Specify the color scale to use in the color axis. Also specify an underflow color 0x66ccff
        # (blue) for regions that fall below the lower axis limit.
        $colorScale = array(0, 0xffff99, 0.2, 0x80cdc1, 0.4, 0x35978f, 0.6, 0x01665e, 0.8, 0x003c30,
            1);
        $cAxis->setColorScale($colorScale, 0x66ccff);
    }

    # Output the chart
    $viewer->setChart($c, SVG);

    # Include tool tip for the chart
    $viewer->setImageMap($c->getHTMLImageMap("", "",
        "title='<*cdml*><*b*>X: {x|2}<*br*>Y: {y|2}<*br*>Z: {z|2}'"));

    # Output Javascript chart model to support contour chart tooltips
    $viewer->setChartModel($c->getJsChartModel());
}

# This example includes 4 charts
$viewers = array();
for ($i = 0; $i < 4; ++$i) {
    $viewers[$i] = new WebChartViewer("chart$i");
    createChart($viewers[$i], $i);
}
?>

<!DOCTYPE html>
<html>
<head>
    <title>Contour Color Scale</title>
    <!-- Include ChartDirector Javascript Library to support chart interactions -->
    <script type="text/javascript" src="cdjcv.js"></script>
</head>
<body style="margin:5px 0px 0px 5px">
    <div style="font:bold 18pt verdana;">
        Contour Color Scale
    </div>
    <hr style="border:solid 1px #000080; background:#000080" />
    <div style="font:10pt verdana; margin-bottom:1.5em">
        <a href="viewsource.php?file=<?=basename(__FILE__)?>">View Chart Source Code</a>
    </div>
    <!-- ****** Here are the chart images ****** -->
    <?php
        for ($i = 0; $i < count($viewers); ++$i) {
            echo $viewers[$i]->renderHTML(), " ";
        }
    ?>
</body>
</html>