CENTROD

Name

centrod

Purpose (one Line)

Compute center of mass of an object aperture.

Description

Calling Sequence

centrod, image, xcen, ycen, radius, inradius, outradius, skyback, $
xbar, ybar, counts

Inputs

image : CCD image array.
xcen, ycen : Center of window.
radius : Radius of window.
inradius : Inner radius of sky annulus.
outradius : Outer radius of sky annulus.
skyback : Sky background in counts per pixel.

Optional Input Parameters

Keyword Parameters

ADDNEG : Flag, if set, the position is computed using both
the moments of counts above and below the background.
Default is to compute the position only using those
image values greater than the sky background.

Outputs

xbar, ybar : Position of center of mass.
counts : Mass of object in counts.

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

Ported by Doug Loucks, Lowell Observatory, 1992 Oct, from the C-
language version written by Marc Buie.
4/1/93, DWL, Added argument validation (badpar).
99/08/31, MWB, added ADDNEG keyword.