.help gseval Aug85 "Gsurfit Package"
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NAME
gseval -- evaluate the fitted surface at x and y
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SYNOPSIS
y = gseval (sf, x, y)

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pointer	sf		# surface descriptor
real	x		# x value, xmin <= x <= xmax
real	y		# y value, ymin <= y <= ymax
.fi
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ARGUMENTS
.ls sf      
Pointer to the surface descriptor structure.
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.ls x, y
X and y values at which the surface is to be evaluated.
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DESCRIPTION
Evaluate the surface at the specified value of x and y. GSEVAL is a real
valued function which returns the fitted value.
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NOTES
GSEVAL uses the coefficient array stored in the surface descriptor structure.
Checking for out of bounds x and y values is the responsibility of the calling
program.
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SEE ALSO
gsvector, gsder
.endhelp