use Chart¶

As with any other Modul you have to:

  use Chart::[Type];

Type being a placeholder for a name of a chart type, which are: Bars, Composite, Direction, ErrorBars, HorizontalBars, Lines, LinesPoints, Mountain, Pareto, Pie, Points, Split, StackedBars. To know more about them read Chart::Manual::Types.

Alternatively write to load all chart types at ones with

  use Chart;

Both are not importing any symbols in your name space but load Carp and GD.

drop data¶

All the methods listed in the last section, that create the final image, take as an optional, second argument data. This data may be delivered either as a reference to an array of arrays:

    my $data = [ [ 1, 4, 3 ... ], # data set 0
                 [ 5, 8, 2 ... ], # data set 1
                 ...
    ];
    $graph->png( 'file.png', $data );

or in form of a file. Then the argument has to be a file name or a file handle (old school as in "FILE" or modern as in $FH). Alternatively use the method add_datafile.

data files¶

Are arbitrary named text files containing one or several rows of numbers, which have to be separated by spaces or tabs (\t) (mixing allowed). Perl style comments or empty lines will be ignored, but rows containing different amount of numbers will cause problems.

create image¶

Currently we support only images in the PNG and JPEG format. The methods to create them are named straight forwardly: ->png and ->jpeg. Both take the same arguments and produce image files. For shell scripting or web programming you need the image binary, which you get with: ->cgi_png or ->cgi_jpeg. Some users might even want the GD object for further processing by your perl programm. In that case please use: ->scalar_png or ->scalar_jpeg.

After having created a chart for web purposes, you also might want to utilize imagemap_dump.