From 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 Mon Sep 17 00:00:00 2001 From: Joe Hunkeler Date: Tue, 11 Aug 2015 16:51:37 -0400 Subject: Repatch (from linux) of OSX IRAF --- math/iminterp/doc/asieval.hlp | 44 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 math/iminterp/doc/asieval.hlp (limited to 'math/iminterp/doc/asieval.hlp') diff --git a/math/iminterp/doc/asieval.hlp b/math/iminterp/doc/asieval.hlp new file mode 100644 index 00000000..20f70abe --- /dev/null +++ b/math/iminterp/doc/asieval.hlp @@ -0,0 +1,44 @@ +.help asieval Dec98 "Image Interpolator Package" +.ih +NAME +asieval -- procedure to evaluate interpolant at x +.ih +SYNOPSIS +y = asieval (asi, x) + +.nf + pointer asi #I interpolant descriptor + real x[2] #I x value, 1 <= x[1-2] <= npts +.fi +.ih +ARGUMENTS +.ls asi +Pointer to the sequential interpolant descriptor structure. +.le +.ls x +Single X value, or pair of X values defining a range in the case of the +drizzle interpolant. +.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 interval. +.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 using ASIEVAL. +.ih +SEE ALSO +asivector, arieval +.endhelp -- cgit