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

.nf
    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
.ih
ARGUMENTS
.ls msi     
Pointer to the interpolant descriptor structure.
.le
.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.
.le
.ls zfit
The array of interpolated points.
.le
.ls nx, ny
The number of points in the x and y directions respectively.
.le
.ls len_zfit
The row length of the zfit array. Len_zfit >= nx.
.le
.ih
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.
.ih
NOTES
Checking for out of bounds and INDEF valued pixels is the responsibility
of the user.
.ih
SEE ALSO
msieval, msivector, msider, mrieval, mrider
.endhelp
