subroutine pda_splev(t,n,c,k,x,y,m,ier)
subroutine pda_splev evaluates in a number of points x(i),i=1,2,...,m
a spline s(x) of degree k, given in its b-spline representation.
calling sequence:
call pda_splev(t,n,c,k,x,y,m,ier)
input parameters:
t : array,length n, which contains the position of the knots.
n : integer, giving the total number of knots of s(x).
c : array,length n, which contains the b-spline coefficients.
k : integer, giving the degree of s(x).
x : array,length m, which contains the points where s(x) must
be evaluated.
m : integer, giving the number of points where s(x) must be
evaluated.
output parameter:
y : array,length m, giving the value of s(x) at the different
points.
ier : error flag
ier = 0 : normal return
ier =10 : invalid input data (see restrictions)
restrictions:
m >= 1
t(k+1) <= x(i) <= x(i+1) <= t(n-k) , i=1,2,...,m-1.
other subroutines required: pda_fpbspl.
references :
de boor c : on calculating with b-splines, j. approximation theory
6 (1972) 50-62.
cox m.g. : the numerical evaluation of b-splines, j. inst. maths
applics 10 (1972) 134-149.
dierckx p. : curve and surface fitting with splines, monographs on
numerical analysis, oxford university press, 1993.
author :
p.dierckx
dept. computer science, k.u.leuven
celestijnenlaan 200a, b-3001 heverlee, belgium.
e-mail : Paul.Dierckx@cs.kuleuven.ac.be
latest update : march 1987