.help msigrid Dec98 "Image Interpolation Package"
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NAME
msigrid -- evaluate the interpolant on a grid of points
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SYNOPSIS
msigrid (msi, x, y, zfit, nx, ny, len_zfit)

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    pointer	msi			#I interpolant descriptor
    real	x[2*nx]			#I x values, 1 <= x[i] <= nx
    real	y[2*ny]  		#I y values, 1 <= y[i] <= ny
    real	zfit[len_zfit,ARB]	#O grid of interpolated values
    int		nx			#I number of x points
    int		ny			#I number of y points
    int		len_zfit		#I length zfit, len_zfit >= nx
.fi
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ARGUMENTS
.ls msi     
Pointer to the interpolant descriptor structure.
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.ls x, y
The x and y arrays of points to be evaluated, or in the case of the drizzle
interpolant the x and y ranges over which the points are to be evaluated.
The x and y arrays must be ordered in increasing values of x and y respectively.
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.ls zfit
The array of interpolated points.
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.ls nx, ny
The number of points in the x and y directions respectively.
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.ls len_zfit
The row length of the zfit array. Len_zfit >= nx.
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DESCRIPTION
MSIGRID evaluates the interpolant at a set of x and y values on a
rectangular grid or in the case of the drizzle interpolant within
rectangular regions. It is most efficient for evaluating the interpolant
at many values which are closely spaced in x and y. For widely spaced
points MSIVECTOR should be used.
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NOTES
Checking for out of bounds and INDEF valued pixels is the responsibility
of the user.
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SEE ALSO
msieval, msivector, msider, mrieval, mrider
.endhelp