Density and Contour Plots, and multiplot

[mleoking]

First of all I really like gral. I investigated many Java plotting libs and found only two of them are attractive and interesting: XChart and Gral. I tried to use both in my research, but had to give up and use Gnuplot instead (I even created a java API for it https://github.com/mleoking/JavaGnuplotHybrid). Because both of xchart and gral lack the two important features:

1. Density and Contour Plots

http://reference.wolfram.com/mathematica/tutorial/DensityAndContourPlots.html

In academic publications, Density and Contour Plots are frequently used as a better replacement for 3D plots. Density and Contour Plots map the value of the third axis (z-axis) to different colors on a 2D figure.

Here is a example contour and density plot:

This type of plot can complete the plot functions of gral. And it is easier to implement and use than 3D charts.

1. Multiplot

http://www.gnuplot.info/demo_svg_5.0/layout.html

Multiplot is another essential feature for producing high-quality academic graphs. Here is an example multiplot:

Multiplot has to be done natively by a plotting lib rather using photo processing tools to combine two graphs. Because those photo processing tools will zoom the size of the label in the axes when zooming a sub-graph. Only native support from a plotting lib can keep the size of the axis labels of a sub-graph to the same as that of the main-graph when zooming a sub-graph.

I really hope gral can put these two very important features in the agenda.

[eseifert]

First of all, thanks a lot for your detailed feedback! Contour plots have been on the unofficial agenda for some time already. I would also like to see multi-plots in GRAL, and this feature has been requested before as well. We'll try to implement both, but unfortunately, I can't give a time frame yet.