[haskell-gnuplot] plot multiple histogram on the same screen

[Henning Thielemann]

Sorry, Roman, I missed your mail and found it accidentally when looking 
into the archive. My plan is to keep the Simple interface simple, since it 
can hardly cope with all combinations of Gnuplot features. It shall be the 
choice for interactive work in GHCi. Additionally I started to develop an 
advanced interface for programmed plots. See e.g. how the functions in 
Simple are implemented today:
   http://code.haskell.org/gnuplot/src/Graphics/Gnuplot/Simple.hs

The idea is to build and combine objects and finally plot them through 
gnuplot.

Because of the increased interest in advanced plots, I should invest some 
effort in the gnuplot wrapper quickly. :-)