From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001 From: Joseph Hunkeler Date: Wed, 8 Jul 2015 20:46:52 -0400 Subject: Initial commit --- math/iminterp/doc/asivector.hlp | 52 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 math/iminterp/doc/asivector.hlp (limited to 'math/iminterp/doc/asivector.hlp') diff --git a/math/iminterp/doc/asivector.hlp b/math/iminterp/doc/asivector.hlp new file mode 100644 index 00000000..95bac138 --- /dev/null +++ b/math/iminterp/doc/asivector.hlp @@ -0,0 +1,52 @@ +.help asivector Dec98 "Image Interpolator Package" +.ih +NAME +asivector -- evaluate the interpolant +.ih +SYNOPSIS +asivector (asi, x, y, npix) + +.nf + pointer asi #I interpolator descriptor + real x[npix/2*npix] #I x array, 1 <= x[i] <= npix + real y[npix] #O array of interpolated values + int npix #I number of x values +.fi +.ih +ARGUMENTS +.ls asi +Pointer to the sequential interpolator descriptor structure. +.le +.ls x +Array of npix x values, or array of npix x ranges if the interpolant is +drizzle. +.le +.ls y +Array of interpolated values. +.le +.ls npix +The number of x values. +.le +.ih +DESCRIPTION +The polynomial coefficients are calculated directly from the data points +for the polynomial interpolants, and from the B-spline coefficients for +the cubic spline interpolant. The actual calculation is done by adding and +multiplying terms according to Everett's central difference interpolation +formula. The boundary extension algorithm is projection. + +The sinc interpolant is computed using a range of data points around +the desired position. Look-up table sinc interpolation is computed +using the most appropriate entry in a precomputed look-up table. +The boundary extension algorithm is nearest neighbor. + +The drizzle interpolant is computed by summing the data over the user +supplied X intervals. +.ih +NOTES +Checking for out of bounds and INDEF valued pixels is the responsibility of the +user. ASIINIT or ASISINIT and ASIFIT must be called before calling ASIVECTOR. +.ih +SEE ALSO +asieval, asider, arieval, arider +.endhelp -- cgit