NAME
axes - determine the centroid and width of an object
SYNOPSIS
axes file [box=] [sky=]
DESCRIPTION
This routine computes the location of the object by calculating a gaussian
fit to the marginal light distribution inside the box specified. The sky
value may be entered in the command line to have the bias values removed
before the moments are calculated. The routine also calculates a two measures
of the FWHM around the centroid by fitting a 1-d gaussian to radial light
distribution.
peak),
If the XVista SKY variable has a non-zero value, it is used as the sky
background value unless overridden on the command line. If no sky value is
supplied either on the command line or via the SKY variable, the routine uses
the maximum pixel value along the edges of the box as the sky
value.
EXAMPLE
axes lyr box=1
- finds the centroid of the object in box 1 in file lyr.
axes alflyr box=2 sky=45
- finds the centroid of the object in box 2 of the
file alflyr, using a sky value of
45.
SYMBOLS
The symbols AXR and AXC are set to the centroid values of row and column,
respectively.
BUGS
It is not possible to specify a SKY value of between -1.5 and -2.5. The
FWHM often overestimates non-gaussian
objects.
SEE ALSO
sky