Curve fitting

[Tom Anderson]

Hi,

I'd like to fit a curve (a rectangular hyperbola, in fact) to some data
points as part of a program i'm writing. Can anyone suggest a package
which would help me do this?

A bit of googling suggests that SciPy might be what i want. Does that
sound likely?

Thanks,
tom

 

[Grant Edwards]

I'd like to fit a curve (a rectangular hyperbola, in fact) to
some data points as part of a program i'm writing. Can anyone
suggest a package which would help me do this?

I use the LeastSquares function in Scientific Python:

http://starship.python.net/~hinsen/ScientificPython/

A bit of googling suggests that SciPy might be what i want.
Does that sound likely?

Sure.

 

[Tom Anderson]

I use the LeastSquares function in Scientific Python:

http://starship.python.net/~hinsen/ScientificPython/

I'll check that out, cheers.

Sure.

I ended up using scipy.optimize.minpack.leastsq, and it works brilliantly.
The interface is a bit awkward - it wants a function from a guess at the
parameters to a list of residuals; i'd rather give it a function from
parameters + x-coordinate to y-coordinate plus a set of points, and have
it work out the residuals for me - so i wrote a little wrapper to make it
suit me better, and now i'm cooking with gas. The only problem is that the
optimisation doesn't converge, but i think that's probably a bug in my
code!

tom