GETANNUL

Name

getannul

Purpose (one Line)

Extract an annulus from a 2-D array.

Description

Calling Sequence

Getannul, image, xcen, ycen, inradius, outradius, data

Inputs

image : CCD image array.
xcen,ycen : Center of annulus.
inradius : Radius of inner circle.
outradius : Radius of outer circle.

Optional Input Parameters

Keyword Parameters

Outputs

data : Array of data from the image array.
idx : Optional output of 1D indices (in image) of data.

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

Written by Doug Loucks, Lowell Observatory, April, 1993.
Reference: getannul.c by Marc Buie.
This version is completely different than the previous version and
somewhat faster.
5/12/93, DWL, Fixed a bug involving fringe pixels. In certain cases,
the determination of the row indices led to a bad array
subscript range.
1/5/94, DWL, Added optional output parameter idx.
95/06/12, MWB, Fixed bug, base needed to be LONG for large sky apertures