Readme file for Chart::Plot - Plot two dimensional data in an image. I wrote Chart::Plot to create images of some simple graphs of two dimensional data. The other graphing interface modules to GD.pm I saw on CPAN either could not handle negative data, or could only chart evenly spaced horizontal data. (If you have evenly spaced or nonmetric horizontal data and you want a bar or pie chart, you should try the GD::Graph and Chart::* modules, available on CPAN.) Chart::Plot will plot multiple data sets in the same graph, each with negative or positive values in the independent or dependent variables. Each dataset can be a scatter graph (data are represented by graph points only) or with lines connecting successive data points, or both. Colors and dashed lines are supported, as is scientific notation (1.7E10). Axes are scaled and positioned automatically and 5-10 ticks are drawn and labeled on each axis. You must have already installed the GD.pm library by Lincoln Stein, available on CPAN or at http://stein.cshl.org/WWW/software/GD/ Early versions of GD (1.19 and earlier) supported only gif format; more recent versions support only png format. Version 1.27 also supports jpeg format. All these versions are still available. Chart::Plot will draw either gif or png by default depending on your version of GD, and will draw jpeg if you request and it is available. This is a beta software and has not received exhaustive testing, but it seems to mostly work ok. Tick labels when using scientific notation seem to run together too often. There are a several features that it doesn't have but should, and the code could be improved in a few places. I will try to maintain compatibility of the public interface if there are future versions. Installation: unzip and untar the distribution and move into its directory. Then the usual perl Makefile.PL make make test make install 'make test' will produce a few simple images, saved in files in the current directory. I can't think of anything that could go wrong unless you don't have GD.pm installed, but the file 'test.pl' does offer a couple of examples. It also reports your current version of GD and the image format(s) it supports, but this could later change if GD is up(down)graded. There is also a sample cgi script, demo.cgi (which uses CGI.pm) that I have used as a front end to Chart::Plot, but please don't write asking me how to install a cgi script. At present time of writing, you can try it at http://www.pobox.com/~smorton/modules/ Sanford Morton