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diff --git a/lib/GD/Graph/FAQ.pod b/lib/GD/Graph/FAQ.pod new file mode 100644 index 0000000..f6ed237 --- /dev/null +++ b/lib/GD/Graph/FAQ.pod @@ -0,0 +1,130 @@ +=head1 NAME + +GD::Graph::FAQ - Frequently asked questions + +=head1 DESCRIPTION + +=head2 I get errors like "Can't call method METHOD on an undefined value". What gives? + +You probably had an error somewhere, most likely in the plot() method, +and you didn't check for it. See the section on Error Handling in the +documentation for L<GD::Graph> to find out how to deal with this sort +of thing, and how to get more information about what the error was. + +=head2 I am drawing a bar chart, and the chart area is a lot smaller than the image. What is going on? + +As of version 1.30, GD::Graph automatically corrects the width of the +plotting area of a chart if it needs to draw bars (i.e. for bars and +some mixed charts). This is necessary, because rounding errors cause +irregular gaps between or overlaps of bars if the bar is not an exact +integer number of pixels wide. + +If you want the old behaviour back, set the correct_with attribute to a +false value. + + +=head2 I have my data in some format that doesn't look at all like the array that I am supposed to give to GD::Graph's plot method. Do I really need to mess around with array references? + +Not necessarily. Check out the GD::Graph::Data class. + + +=head2 How do I stop those pesky accents appearing around bars or inside area charts? + +You can set the C<accent_treshold> option to a large enough value +(larger than your chart). Alternatively, you may like it better to set +the C<borderclrs> attribute to be the same as the dclrs one. + +I'll probably include an option in a future version that gives better +control over this. + + +=head2 Where is the ActiveState ppm of GD::Graph? + +Ask them. I have asked them, but didn't get an answer. I don't know what +to do to get it included in their set of ppms, and I really do not have +the time to keep asking them. + +I believe that GD::graph has finally made it into ActiveState's ppm +archive. However, I am going to leave this question here in case they +get behind again. + + +=head2 Do you have some example code for me? + +The distribution has a large set of examples in it. If you don't have +the original distribution, please get it from CPAN (http://www.cpan.org/ +or some local mirror). + + +=head2 Will you support X or Y? + +If you send me a patch that (in a decent manner) adds the functionality +to the latest version, I may very well add it for the next release. If +you don't send me a patch, but just a question, you will have to be +patient. + +=head2 Why does export_format give me a weird string, instead of just 'png' or 'gif'? + +As of version 1.31, export_format in a list context returns all formats +that GD can export. If you are only interested in the answer 'gif' or +'png', make sure that you call it in a scalar context. + + $export_format = GD::Graph->export_format; + $export_format = $graph->export_format; + print "Export format is ", scalar $graph->export_format, "\n"; + print "Export format is " . $graph->export_format . "\n"; + @export_formats = $graph->export_format; + + +=head2 TrueType fonts don't work when I use GD::Graph from a CGI program. + +When your programs run as CGI, they typically do not have the same +environment as when you use them from the command line. The Perl FAQ, +section 9, has some information on this. It is also not guaranteed that +your script runs from the directory that it is in. It is probably better +to include something like: + + use GD::Text; + GD::Text->font_path("/path/to/my/font_dir"); + +See the GD::Text documentation for more information about font paths. + +=head2 I'm trying to use GD's builtin fonts, but it's not working. + +Most likely, you are using the font short name, like gdGiantFont or +gdMediumBoldFont, and you have not put a C<use GD> in your program. +This is needed, because these short names need to be exported into +your name space by the GD library: + + use GD; + # ... + $graph->set_x_axis_font(gdMediumBoldFont); + +If you don't want to include the GD library, you can use the +longer alternative names (which is what I'd recommend anyway): + + $graph1->set_x_axis_font(GD::Font->MediumBold); + +If you C<use strict> then you will actually get an error message if +you try to use the short names without including the GD module. + +Also see the L<GD::Text> documentation for this information. + +=head2 When I have many data sets, some end up having the same colour. + +The default number of colours for data sets is seven, so if you use +more than seven data sets, those colours will be re-used for the +higher data sets. + +This is described in the entry for the C<dclrs> attribute in the +L<GD::Graph> documentation. + +=head1 AUTHOR + +Martien Verbruggen E<lt>mgjv@tradingpost.com.auE<gt> + +(c) Martien Verbruggen. + +All rights reserved. This package is free software; you can redistribute +it and/or modify it under the same terms as Perl itself. + |
