.help islrefit Aug85 "Gsurfit Package"
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NAME
islrefit -- refit surface grid line  assuming old cols, w vector
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SYNOPSIS
include <math/surfit.h>

islrefit (sf, cols, lineno, z, w)

.nf
pointer	sf			# surface grid descriptor
int	cols[ARB]		# columns to be fit, 1 <= cols[i] <= ncols
int	lineno			# line number of surface grid line to be fit
real	z[ARB]			# array of data values
real	w[ARB]			# array of weights
.fi
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ARGUMENTS
.ls sf          
Pointer to the surface grid descriptor structure.
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.ls cols
The column numbers of the surface grid line to be added to the dataset.
.le
.ls lineno
The number of the surface grid line to be added to the dataset.
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.ls z    
Array of data values.
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.ls w    
Array of weights.
.le
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DESCRIPTION
In some applications the cols, and w values remain unchanged from fit
to fit and only the z values vary. In this case it is redundant to
reaccumulate the matrix and perform the Cholesky factorization for each
succeeding surface grid line. ISLREFIT
zeros and reaccumulates the vector on the right hand side of the matrix
equation and performs the forward and back substitution phase to fit for
a new coefficient vector.
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NOTES
It is the responsibility of the calling program to check for out of bounds
column values and INDEF valued pixels.
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SEE ALSO
isinit, islfit, islaccum, islsolve, islzero, issolve, isfree
.endhelp