<?php
require_once("../lib/phpchartdir.php");

# XY points for the scatter chart
$dataX0 = array(100, 150, 60, -120, 140, -80, 130, -130, 160, 120, 105);
$dataY0 = array(130, 150, 80, 110, -110, -105, -130, 115, -170, 125, 125);

# Create a XYChart object of size 600 x 300 pixels, with a light blue (ccccff)
# background, a black border, and 1 pixel 3D border effect
$c = new XYChart(600, 480, 0xccccff, 0x000000, 1);

# Add a title box to the chart using 16 pts Arial Bold Italic font, with white text
# on deep blue background
$textBoxObj = $c->addTitle("Four Quadrant Chart Demonstration", "arialbi.ttf", 16,
    0xffffff);
$textBoxObj->setBackground(0x000080);

# Set the plotarea at (20, 60) and of size 560 x 360 pixels, with grey (808080)
# border, and light grey (c0c0c0) horizontal and vertical grid lines. Set 4 quadrant
# coloring, where the colors of the quadrants alternate between lighter and deeper
# grey (dddddd/eeeeee)
$plotAreaObj = $c->setPlotArea(20, 60, 560, 360, -1, -1, 0x808080, 0xc0c0c0, 0xc0c0c0
    );
$plotAreaObj->set4QBgColor(0xdddddd, 0xeeeeee, 0xdddddd, 0xeeeeee);

# Set 4 quadrant mode, with both x and y axes symetrical around the origin
$c->setAxisAtOrigin(XYAxisAtOrigin, XAxisSymmetric + YAxisSymmetric);

# Add a legend box at (300, 460) (bottom center of the chart) with horizontal layout.
# Use 8 pts Arial Bold font.
$legendBox = $c->addLegend(300, 460, false, "arialbd.ttf", 8);
$legendBox->setAlignment(BottomCenter);

# Set legend box background to light grey (dddddd) with a black border
$legendBox->setBackground(0xdddddd, 0);

# Set left/right margin to 20 pixels and top/bottom margin to 5 pixels
$legendBox->setMargin2(20, 20, 5, 5);

# Add a titles to axes
$c->xAxis->setTitle("Alpha Index");
$c->yAxis->setTitle("Beta Index");

# Set axes width to 2 pixels
$c->xAxis->setWidth(2);
$c->yAxis->setWidth(2);

# Add scatter layer, using 15 pixels red (ff33333) X shape symbols
$c->addScatterLayer($dataX0, $dataY0, "Group A", Cross2Shape(), 15, 0xff3333);

$minXData = min($dataX0);
$maxXData = max($dataX0);
$minYData = min($dataY0);
$maxYData = max($dataY0);

$xValuePerPixel = ($maxXData - $minXData) / $c->getPlotArea()->getWidth();
$yValuePerPixel = ($maxYData - $minYData) / $c->getPlotArea()->getHeight();
$valuePerPixel = max($xValuePerPixel, $yValuePerPixel);
if ($valuePerPixel > $xValuePerPixel) {
    $delta = ($valuePerPixel - $xValuePerPixel) * $c->getPlotArea()->getWidth();
    $maxXData = $maxXData + $delta / 2;
    $minXData = $minXData - $delta / 2;
}
if ($valuePerPixel > $yValuePerPixel ) {
    $delta = ($valuePerlPixel - $yValuePerPixel) * $c->getPlotArea()->getHeight();
    $maxYData = $maxYData + $delta / 2;
    $minYData= $minYData- $delta / 2;
}

$c->xAxis->setLinearScale($minXData, $maxXData);
$c->xAxis->setRounding(false, false);

$c->yAxis->setLinearScale($minYData, $maxYData);
$c->yAxis->setRounding(false, false);

# Output the chart
header("Content-type: image/png");
print($c->makeChart2(PNG));
?>