this could be a very "large" solution depending on the size of your data
sets, but you could make a class for your data and then if you make a
change to the data just import it into your drawing code and then redraw
it. this way if you have more than 1 set of data you are just creating
more than one instance of your data class. but if you are using very
large sets of data this could maybe become very slow and ugly.
if you impliment your data class well enough you could make it so that you
have functions in the data class that "add the new stuff" that you need
to. I'm currently working with a graph that has 6000+ plots of data I am
picking subplots from it and applying a cubic integration to it. It runs
in a timely manner and i have no complaints.
Does someone know of a convenient way to save a plotted figure in order to
reloading it later, possible adding new stuffs to it ? Presently, i keep
pickling my data and cut&pasting my drawing code, by hand. I'm interested if
some of you would have better solutions.