Exchanging data with Sketcher does sound like a good approach.
(A pity that it doesn't give direct access to a language for mathematical expressions).

FWIW I've amended the code above to allow OmniGraffle to plot more complex Korn shell expressions like:

2*sin(x)+x

or

pow(x,2)+(4*x)-5

over a specified range of x.



(It's also a bit faster now, and puts the data into the clipboard, from where, incidentally, it could be pasted straight into OmniGraphSketcher ...)

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