ChartDirector Ver 3.0 (Perl Edition)

Enhanced Line Chart




This example extends the Simple Line Chart example by decorating the chart using a number of chart formatting features.

In this example, random data is used. They are generated using a ChartDirector utility class RanTable. RanTable simulates a database table with the cells filled with random numbers. The columns of the table can be retrieved as arrays using RanTable.getCol.

Source Code Listing

[File: perldemo/enhancedline.pl] (The CGI version is available as "perldemo_cgi/enhancedline.pl".)
#!/usr/bin/perl use perlchartdir; # # We use a random number generator to simulate the data from 9:30 to 4:30 # with one data point every 4 minutes. The total number of points during that # period is 106. (7 hours x 15 points/hour + 1) # my $noOfPoints = 106; #Assume we have not reached the end of the day yet, and only 85 points are #available. Create a random table object of 1 col x 85 rows, using 9 as seed. my $rantable = new RanTable(9, 1, 85); #Set the 1st column to start with 1800 and with random delta from -5 to 5. $rantable->setCol(0, 1800, -5, 5); #Get the data as the 1st column of the random table my $data = $rantable->getCol(0); #The x-axis labels for the chart my $labels = ["-", "10am", "-", " ", "-", "12am", "-", " ", "-", "2pm", "-", " ", "-", "4pm", "-"]; # # Now we obtain the data into arrays, we can start to draw the chart using # ChartDirector # #Create a XYChart object of size 180 x 180 pixels with a blue background #(0x9c9cce) my $c = new XYChart(180, 180, 0x9c9cce); #Add titles to the top and bottom of the chart using 7.5pt Arial font. The text #is white 0xffffff on a deep blue 0x31319C background. $c->addTitle2($perlchartdir::Top, "STAR TECH INDEX 2003-01-28", "arial.ttf", 7.5, 0xffffff, 0x31319c); $c->addTitle2($perlchartdir::Bottom, "LATEST STI:1809.41 (+14.51)", "arial.ttf", 7.5, 0xffffff, 0x31319c); #Set the plotarea at (31, 21) and of size 145 x 124 pixels, with a pale yellow #(0xffffc8) background. $c->setPlotArea(31, 21, 145, 124, 0xffffc8); #Add custom text at (176, 21) (top right corner of plotarea) using 11pt Times #Bold Italic font/red (0xc09090) color $c->addText(176, 21, "Chart Demo", "timesbi.ttf", 11, 0xc09090)->setAlignment( $perlchartdir::TopRight); #Use 7.5 pts Arial as the y axis label font $c->yAxis()->setLabelStyle("", 7.5); #Set the labels on the x axis by spreading the labels evenly between the first #point (index = 0) and the last point (index = noOfPoints - 1) $c->xAxis()->setLinearScale(0, $noOfPoints - 1, $labels); #Use 7.5 pts Arial as the x axis label font $c->xAxis()->setLabelStyle("", 7.5); #Add a deep blue (0x000080) line layer to the chart $c->addLineLayer($data, 0x80); #output the chart $c->makeChart("enhancedline.png")