ImageD11.bisplev | index /sware/exp/fable/standalone/redhate4-a64/lib/python2.5/site-packages/ImageD11/bisplev.py

`Interface to the bispev bit of fitpack.
fitpack (dierckx in netlib) --- A Python-C wrapper to FITPACK (by P. Dierckx).
FITPACK is a collection of FORTRAN programs for CURVE and SURFACE
FITTING with SPLINES and TENSOR PRODUCT SPLINES.
See
http://www.cs.kuleuven.ac.be/cwis/research/nalag/research/topics/fitpack.html
or
http://www.netlib.org/dierckx/index.html
(I think) This code was copied from fitpack.py and modified by J. P. Wright
so as to avoid having to install all of scipy. Hence the following notice:
Copyright 2002 Pearu Peterson all rights reserved,
Pearu Peterson <pearu@cens.ioc.ee>
Permission to use, modify, and distribute this software is given under the
terms of the SciPy (BSD style) license. See LICENSE.txt that came with
scipy for specifics.
NO WARRANTY IS EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
Pearu Peterson`

Modules
`` |  |
ImageD11._splines | numpy.oldnumeric |  |

Functions
`` |  | bisplev(x, y, tck, dx=0, dy=0) `Evaluate a bivariate B-spline and its derivatives. Description: Return a rank-2 array of spline function values (or spline derivative values) at points given by the cross-product of the rank-1 arrays x and y. In special cases, return an array or just a float if either x or y or both are floats. Inputs: x, y -- Rank-1 arrays specifying the domain over which to evaluate the spline or its derivative. tck -- A sequence of length 5 returned by bisplrep containing the knot locations, the coefficients, and the degree of the spline: [tx, ty, c, kx, ky]. dx, dy -- The orders of the partial derivatives in x and y respectively. Outputs: (vals, ) vals -- The B-pline or its derivative evaluated over the set formed by the cross-product of x and y.` bisplrep(x, y, z, w=None, xb=None, xe=None, yb=None, ye=None, kx=3, ky=3, task=0, s=None, eps=9.9999999999999998e-17, tx=None, ty=None, full_output=0, nxest=None, nyest=None, quiet=1) `Find a bivariate B-spline representation of a surface. Description: Given a set of data points (x[i], y[i], z[i]) representing a surface z=f(x,y), compute a B-spline representation of the surface. Inputs: x, y, z -- Rank-1 arrays of data points. w -- Rank-1 array of weights. By default w=ones(len(x)). xb, xe -- End points of approximation interval in x. yb, ye -- End points of approximation interval in y. By default xb, xe, yb, ye = x[0], x[-1], y[0], y[-1] kx, ky -- The degrees of the spline (1 <= kx, ky <= 5). Third order (kx=ky=3) is recommended. task -- If task=0, find knots in x and y and coefficients for a given smoothing factor, s. If task=1, find knots and coefficients for another value of the smoothing factor, s. bisplrep must have been previously called with task=0 or task=1. If task=-1, find coefficients for a given set of knots tx, ty. s -- A non-negative smoothing factor. If weights correspond to the inverse of the standard-deviation of the errors in z, then a good s-value should be found in the range (m-sqrt(2*m),m+sqrt(2*m)) where m=len(x) eps -- A threshold for determining the effective rank of an over-determined linear system of equations (0 < eps < 1) --- not likely to need changing. tx, ty -- Rank-1 arrays of the knots of the spline for task=-1 full_output -- Non-zero to return optional outputs. nxest, nyest -- Over-estimates of the total number of knots. If None then nxest = max(kx+sqrt(m/2),2*kx+3), nyest = max(ky+sqrt(m/2),2*ky+3) quiet -- Non-zero to suppress printing of messages. Outputs: (tck, {fp, ier, msg}) tck -- A list [tx, ty, c, kx, ky] containing the knots (tx, ty) and coefficients (c) of the bivariate B-spline representation of the surface along with the degree of the spline. fp -- The weighted sum of squared residuals of the spline approximation. ier -- An integer flag about splrep success. Success is indicated if ier<=0. If ier in [1,2,3] an error occurred but was not raised. Otherwise an error is raised. msg -- A message corresponding to the integer flag, ier. Remarks: SEE bisplev to evaluate the value of the B-spline given its tck representation.` myasarray(a)