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Basic Information on ellint
Purpose: Integrate a Miriad image in elliptical annuli.
Categories: image analysis
ELLINT integrates a Miriad image in elliptical annuli in the
first two dimensions. E.g. to find the radial brightness
distribution, or flux density as a function of distance in a
galaxy. The integration is done separately for each image plane
in the region included.
The output consists of 6 columns. They are the
outer radius (arcsec) of the annulus;
number of pixels in the annulus;
the average (median) in the annulus;
the rms of the annulus;
the sum in the annulus normalized by the volume of the primary
beam (if there is one);
the cumulative sum for all annuli so far.
Input image name. xyz images only. No default.
Optional output image containing the residuals from the average
values in each annulus. By default this image is not created.
See also options=spline to get better results for noise free
Region of image to be integrated. E.g.
% ellint region=relpix,box(-4,-4,5,5)(1,2)
integrates the center 10 x 10 pixels for image planes 1 and 2.
Unmasked pixels within the bounding box are selected.
The default region is the entire image.
The offset of the center of the annuli in arcsec from the
reference pixel, measured in the directions of RA and DEC.
Position angle of ellipse major axis in degrees. Default is 0
(north). PA is measured in the usual sense, N through E
The ellipse is assumed to be a circular structure that appears
elliptical because it is viewed at some inclination. The
"incline" parameter gives this inclination angle in degrees.
Default=0. (face on)
Inner and outer radii and step size along major axis in arcsecs.
The default is the whole image in steps equal to the pixel size.
If you request that the fluxes be corrected for the primary beam
(see OPTIONS), ELLINT will normally construct a primary beam
type using information from the dataset. However you can
override this with a primary beam type of your own choosing.
The primary beam type can either be a telescope name whose
primary beam is known (e.g. Hatcreek, VLA, ATCA, etc) or you can
select a Gaussian form with "gaus(xxx)". Here xxx is the
primary beam FWHM in arcseconds. For example gaus(120) is a
telescope with a 120 arcsec primary beam.
Scale factor applied to the amplitudes before printing them.
Task enrichment options. Minimum match is active.
pbcorr This causes the images to be corrected for primary
beam attenutation before integrating.
median Find the median of each annulus instead of the
mode Find the mode of each annulus instead of the
natural Assume keywords "center" and "radius" are in natural
units rather than arcsec.
table Output ring data in logfile. No fitting done.
Logfile now contains coordinates w.r.t. the
reference pixel (in arcsec), the image value, and
the radius in the disk defined by PA and INCLINE.
spline use a spline fit unstead of a step function to
estimate the intensity at any radius for residual
Smoothing option of radial profile when option=median is used
in residual map computation. Default: 0
The output log file. The default is the terminal.
Revision: 1.6, 2010/11/22 06:27:38 UTC
Generated by email@example.com on 26 May 2011