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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <math/curfit.h>
include "curfitdef.h"
# CVFIT -- Procedure to add a set of points to the normal equations.
# The inner products of the basis functions are calculated and
# accumulated into the CV_ORDER(cv) by CV_NCOEFF(cv) matrix MATRIX.
# The main diagonal of the matrix is stored in the first row of
# MATRIX followed by the remaining non-zero diagonals. This method
# of storage is particularly efficient for the large symmetric
# banded matrices produced during spline fits. The inner product
# of the basis functions and the data ordinates are stored in the
# CV_NCOEFF(cv)-vector VECTOR. The array LEFT is
# used for the indices describing which elements of MATRIX and VECTOR are
# to receive the inner products. After accumulation is complete
# the Cholesky factorization of MATRIX is calculated and stored
# in the CV_ORDER(cv) by CV_NCOEFF(cv) matrix CHOFAC. Finally
# the coefficients are calculated by forward and back substitution
# and placed in COEFF.
procedure cvfit (cv, x, y, w, npts, wtflag, ier)
pointer cv # curve descriptor
real x[npts] # array of abcissa
real y[npts] # array of ordinates
real w[npts] # array of weights
int npts # number of data points
int wtflag # type of weighting
int ier # error code
begin
# zero the appropriate arrays
call cvzero (cv)
# enter data points
call cvacpts (cv, x, y, w, npts, wtflag)
# solve the system
call cvsolve (cv, ier)
end
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