.help iscoeff Apr85 "Surfit Package"
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NAME
iscoeff - get the number and values of the surface coefficients
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SYNOPSIS
iscoeff (sf, coeff, ncoeff)

.nf
pointer	sf		# surface descriptor
real	coeff[ncoeff]	# coefficient array
int	ncoeff		# number of coefficients
.fi
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ARGUMENTS
.ls sf   
Pointer to the surface descriptor.
.le
.ls coeff
Array of coefficients.
.le
.ls ncoeff
The number of coefficients.
.le

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DESCRIPTION
ISCOEFF fetches the coefficient array and the number of coefficients from
the surface descriptor structure. A 1-D array ncoeff elements long
is required to hold the coefficients where ncoeff is defined as follows:

.nf
	SF_LEGENDRE:		nxcoeff = xorder
				nycoeff = yorder
				ncoeff = xorder * yorder        xterms = yes
				ncoeff = nycoeff + nxcoeff - 1  xterms = no

	SF_CHEBYSHEV:		nxcoeff = xorder
				nycoeff = yorder
				ncoeff = xorder * yorder        xterms = yes
				ncoeff = nycoeff + nxcoeff - 1  xterms = no

	SF_SPLINE3:		nxcoeff = xorder + 3
				nycoeff = yorder + 3
				ncoeff = (xorder + 3) * (yorder + 3)

	SF_SPLINE1:		nxcoeff = xorder + 1
				nycoeff = yorder + 1
				ncoeff = (xorder + 1) * (yorder + 1)

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The coefficient of basis function B(i,x) * B(j,y) will be stored in
element (i - 1) *
nycoeff + j of the array coeff if the xterms parameter was set
to yes by ISINIT. Otherwise the nycoeff y-term coefficients will be output
first followed by the (nxcoeff - 1) x-term coefficients.

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NOTES
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SEE ALSO
.endhelp
