Nice interpolation

First, I want to thank John Hunter and Jouni Seppanen for

    > their very useful help with my xticklabel problems. I
    > have little experience with python, and am a total newbie
    > wrt. matplotlib (- which is very impressive...).

Thanks!

    > Few days ago I was looking for a method to interpolate
    > 12hourly data, and was not happy with the python
    > alternatives I found. I wanted something in native
    > python, not wrappers to C or Fortran programs (in this

I think the best reason for writing it up in python is that it is fun
and instructive, but I don't agree with the "not wrappers of C or
Fortran". Note that pylab is built on top of Numeric, which is
written in C, the font handling is built on top of freetype, another C
library, and the antigrain renderer engine is a C++ library.
matplotlib ships with a fair amount of C/C++ code, and scipy does the
same for C, C++ and FORTRAN. The strength of python is its fluid
integration with other languages.

Also, the agg engine provides many 2d interpolation algorithms:

    nearest, bilinear, bicubic, spline16, spline36, hanning, hamming,
    hermite, kaiser, quadric, catrom, gaussian, bessel, mitchell,
    sinc, lanczos, blackman

It would be nice to provide a more direct interface to these, and
other agg image functionality, in matplotlib.

Thanks for your code -- you may also want to look at scipy.interpolate

NAME
    scipy.interpolate

FILE
    /usr/lib/python2.4/site-packages/scipy/interpolate/__init__.py

DESCRIPTION
    Interpolation Tools

···

===================

    Wrappers around FITPACK functions:

      splrep -- find smoothing spline given (x,y) points on curve.
      splprep -- find smoothing spline given parametrically defined
      curve.
      splev -- evaluate the spline or its derivatives.
      splint -- compute definite integral of a spline.
      sproot -- find the roots of a cubic spline.
      spalde -- compute all derivatives of a spline at given
      points.
      bisplrep -- find bivariate smoothing spline representation.
      bisplev -- evaluate bivariate smoothing spline.

    Interpolation Class

      interp1d -- Create a class whose instances can linearly
      interpolate
                   to compute unknown values.