Line with Error Symbols

This example demonstrates combining a line layer with a box-whisker layer to draw a line with error symbols.

The blue line and the yellow diamond symbols are from the line layer, created using XYChart.addLineLayer2, Layer.addDataSet, and DataSet.setDataSymbol.

The error symbols come from the box-whisker layer, created using XYChart.addBoxWhiskerLayer. In this example, the "box" parts of the box- whisker symbols are disabled by setting the data for the box and median to empty arrays. As a result, only the "whisker" parts of the box-whisker symbols are visible and they become the error symbols.

The maximum and minimum marks in this example is computed by adding/subtracting the error value to/from the data value using a ChartDirector utility class ArrayMath.

[File: phpdemo/errline.php]

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

# The data with error information
$data = array(42, 49, 33, 38, 51, 46, 29, 41, 44, 57, 59, 52, 37, 34, 51, 56, 56, 60,
    70, 76, 63, 67, 75, 64, 51);
$errData = array(5, 6, 5.1, 6.5, 6.6, 8, 5.4, 5.1, 4.6, 5.0, 5.2, 6.0, 4.9, 5.6, 4.8,
    6.2, 7.4, 7.1, 6.0, 6.6, 7.1, 5.3, 5.5, 7.9, 6.1);

# The labels for the chart
$labels = array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12",
    "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24");

# Create a XYChart object of size 600 x 300 pixels, with a light grey (eeeeee)
# background, black border, 1 pixel 3D border effect and rounded corners.
$c = new XYChart(600, 300, 0xeeeeee, 0x000000, 1);
$c->setRoundedFrame();

#Set directory for loading images to current script directory
#Need when running under Microsoft IIS
$c->setSearchPath(dirname(__FILE__));

# Set the plotarea at (55, 55) and of size 520 x 195 pixels, with white (ffffff)
# background. Set horizontal and vertical grid lines to grey (cccccc).
$c->setPlotArea(55, 55, 520, 195, 0xffffff, -1, -1, 0xcccccc, 0xcccccc);

# Add a title box to the chart using 15 pts Times Bold Italic font. The title is in
# CDML and includes embedded images for highlight. The text is on a light grey
# (dddddd) background, with glass lighting effect.
$textBoxObj = $c->addTitle(
    "<*block,valign=absmiddle*><*img=star.png*><*img=star.png*> Molecular ".
    "Temperature Control <*img=star.png*><*img=star.png*><*/*>", "timesbi.ttf", 15);
$textBoxObj->setBackground(0xdddddd, 0, glassEffect());

# Add a title to the y axis
$c->yAxis->setTitle("Temperature");

# Add a title to the x axis using CMDL
$c->xAxis->setTitle(
    "<*block,valign=absmiddle*><*img=clock.png*>  Elapsed Time (hour)<*/*>");

# Set the labels on the x axis.
$c->xAxis->setLabels($labels);

# Display 1 out of 3 labels on the x-axis. Show minor ticks for remaining labels.
$c->xAxis->setLabelStep(3, 1);

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

# Add a line layer to the chart
$lineLayer = $c->addLineLayer2();

# Add a blue (0xff) data set to the line layer, with yellow (0xffff80) diamond
# symbols
$dataSetObj = $lineLayer->addDataSet($data, 0x0000ff);
$dataSetObj->setDataSymbol(DiamondSymbol, 12, 0xffff80);

# Set the line width to 2 pixels
$lineLayer->setLineWidth(2);

# Add a box whisker layer to the chart. Use the upper and lower mark of the box
# whisker layer to act as error zones. The upper and lower marks are computed using
# the ArrayMath object.
$upperMark = new ArrayMath($data);
$upperMark->add($errData);

$lowerMark = new ArrayMath($data);
$lowerMark->sub($errData);

$errLayer = $c->addBoxWhiskerLayer(null, null, $upperMark->result(),
    $lowerMark->result(), $data, Transparent, 0xbb6633);

# Set the line width to 2 pixels
$errLayer->setLineWidth(2);

# Set the error zone to occupy half the space between the symbols
$errLayer->setDataGap(0.5);

# Add a custom CDML text at the bottom right of the plot area as the logo
$textBoxObj = $c->addText(575, 247,
    "<*block,valign=absmiddle*><*img=small_molecule.png*> <*block*>".
    "<*font=timesbi.ttf,size=10,color=804040*>Molecular\nEngineering<*/*>");
$textBoxObj->setAlignment(BottomRight);

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