[SciPy-dev] Fitpack, insert, and spline -> bezier conversion

Zachary Pincus zpincus@stanford....
Tue Feb 6 20:33:46 CST 2007

Hello all,

I've been working with scipy.interpolate a lot lately (hence some of  
the noise on this list; sorry) to write some code to convert cubic  
parametric b-splines into bezier curves (for easy output to things  
like postscript or SVG).

With the FITPACK 'insert' routine wrapped, this is relatively easy  
once you figure out how, although there are a few gotchas. (Would  
such a bit of code be useful in the scipy fitpack library?)

In the course of writing these conversion functions, I came upon some  
subtle bugs in the original implementation of insert.f from netlib.  
(They have to do with how the range into which the knot will be  
inserted is chosen in corner cases that occur when converting  
periodic splines to bezier curves.) I've tried contacting Dr.  
Dierckx, but so far without luck.

What would be the best approach to making sure that at least scipy  
gets correct versions? Should I contact the netlib people? Should I  
send you guys my patch and further fork the codebase?



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