pwtools.num.PolyFit

class pwtools.num.PolyFit(points, values, *args, **kwds)[source]

Bases: object

High level interface to poly{fit,val}, similar to Spline and Interpol2D.

Arguments and keywords to __init__() are the same as for polyfit(). Keywords to __call__() are same as for polyval().

Parameters:

  • points (nd array (npoints,ndim)) – npoints points in ndim-space, to be fitted by a ndim polynomial f(x0,x1,…,x{ndim-1}).

  • values (1d array)

  • deg (int) – Degree of the poly (e.g. 3 for cubic).

  • scale (bool, optional) – Scale points and values to unity internally before fitting.

Notes

__init__: points must be (npoints,ndim) even if ndim=1.
__call__: points can be (ndim,) instead of (1,ndim), need this if called in fmin()

Examples

>>> fit1=polyfit(points, values, deg=3); polyval(fit1, new_points)
>>> # the same
>>> f1=PolyFit(points, values, 3); f1(new_points)
__init__(points, values, *args, **kwds)[source]
Parameters:

  • points (nd array (npoints, ndim))

  • values (1d array (npoints,))

  • **kwds (keywords to polyfit())

__call__(points, **kwds)[source]

Call self as a function.

Methods

get_min([x0])

Minimize fit function by scipy.optimize.fmin().