[SciPy-user] spline interpolation

Robert Kern robert.kern at gmail.com
Thu Nov 9 17:19:28 CST 2006


Jordan Dawe wrote:
> Robert Kern wrote:
>> Jordan Dawe wrote:
>>> I've been looking at scipy's interpolation routines and I can't make
>>> heads or tails of them.  I just want to do a spline interp1d like matlab
>>> does.  Is there any way to do this?
>>
>> I don't know exactly what features you want from Matlab's interp1d, but you
>> probably want scipy.interpolate.UnivariateSpline.
> I want a cubic spline fit that passes through every point it is fit to. 
> I haven't been able to figure out how to make UnivariateSpline do this;
> it goes near the points, but is not constrained to satisfy the points
> exactly.  Matlab does this by a series of piecewise spline
> interpolations that are continuous in the first two derivatives at each
> data point.

Did you see the example that I gave you? Passing s=0 as the smoothing parameter
makes the interpolant pass through the given data points. Alternatively,
InterpolatedUnivariateSpline will do this for you.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco


More information about the SciPy-user mailing list