In the area plot, PHPlot fills the area from each data set down to the next data set, or to the X axis for the last data set. For this example, the data was prepared such that the data sets are cumulative percentages. (See also Example 5.21, “Stacked Area Plot” which produces a similar plot using a different data representation.)
Example 5.3. Area Plot
<?php
# PHPlot Example: Area chart, 6 areas.
require_once 'phplot.php';
$data = array(
array('1960', 100, 70, 60, 54, 16, 2),
array('1970', 100, 80, 63, 54, 22, 20),
array('1980', 100, 80, 66, 54, 27, 25),
array('1990', 100, 95, 69, 54, 28, 10),
array('2000', 100, 72, 72, 54, 38, 5),
);
$plot = new PHPlot(800, 600);
$plot->SetImageBorderType('plain');
$plot->SetPlotType('area');
$plot->SetDataType('text-data');
$plot->SetDataValues($data);
# Main plot title:
$plot->SetTitle('Candy Sales by Flavor');
# Set Y data limits, tick increment, and titles:
$plot->SetPlotAreaWorld(NULL, 0, NULL, 100);
$plot->SetYTickIncrement(10);
$plot->SetYTitle('% of Total');
$plot->SetXTitle('Year');
# Colors are significant to this data:
$plot->SetDataColors(array('red', 'green', 'blue', 'yellow', 'cyan', 'magenta'));
$plot->SetLegend(array('Cherry', 'Lime', 'Lemon', 'Banana', 'Apple', 'Berry'));
# Turn off X tick labels and ticks because they don't apply here:
$plot->SetXTickLabelPos('none');
$plot->SetXTickPos('none');
$plot->DrawGraph();