e01sbf
e01sbf
© Numerical Algorithms Group, 2002.
Purpose
E01SBF Interpolated values, evaluate interpolant computed by E01SAF, two
variables
Synopsis
[pf,ifail] = e01sbf(x,y,f,triang,grads,px,py<,ifail>)
Description
This routine takes as input the parameters defining the
interpolant F(x,y) of a set of scattered data points (x ,y ,f ),
r r r
for r=1,2,...,m, as computed by E01SAF, and evaluates the
interpolant at the point (px,py).
If (px,py) is equal to (x ,y ) for some value of r, the returned
r r
value will be equal to f .
r
If (px,py) is not equal to (x ,y ) for any r, the derivatives in
r r
GRADS will be used to compute the interpolant. A triangle is
sought which contains the point (px,py), and the vertices of the
triangle along with the partial derivatives and f values at the
r
vertices are used to compute the value F(px,py). If the point
(px,py) lies outside the triangulation defined by the input
parameters, the returned value is obtained by extrapolation. In
this case, the interpolating function F is extended linearly
beyond the triangulation boundary.
E01SBF must only be called after a call to E01SAF.
Parameters
e01sbf
Required Input Arguments:
x (:) real
y (:) real
f (:) real
triang (:) real
grads (2,:) real
px real
py real
Optional Input Arguments: <Default>
ifail integer -1
Output Arguments:
pf real
ifail integer