gtkextra example

Hi 

I am trying to compile a small C-program using gtkextra, that I found somewhere
in the web. Unfortunately it is not working. I was able to install
gtk+extra-2-1-2 like described in the readme. But when I try to compile I always
get undefined reference to `gtk_plot_data_get_type' for basically all functions
of gtkextra. I could not figure out how to set the options of the compiler or
miss I something else? Any help is very welcome.  


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