Content-type: text/html Manpage of velimage

velimage

Section: User Commands (1)
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NAME

velimage - Make (x,y,z) image from an (x,y) image and model z-values.  

PERSON RESPONSIBLE

mchw  

CATEGORIES

image analysis  

DESCRIPTION

VELIMAGE is a MIRIAD task to make an (x,y,z) image from an (x,y) image and a model for the z-values and dispersion. The z-values, for example the mean velocity, are input as an (x,y) image, whilst the dispersion can be input as either an (x,y) image or a fixed value. The output image is formed as:-

   out(x,y,z) = in1(x,y) * exp(-(z-in2(x,y))**2/(2*sigma**2)))

VELIMAGE can be used to compare models with the data. For example one can generate a model image corresponding to a rotating galaxy, convolve it with the actual beam and subtract the model from the data to determine if there is residual emission which deviates from the model rotation curve.  

PARAMETERS

in
The input image names, separated by commas. The first image is the (x,y) intensity distribution integrated over the z-axis. No default. e.g. velocity-integrated image. The second image is an (x,y) model for the z-values, e.g. a mean velocity image. No default. A 3rd input image gives the z-dispersion at each point. e.g. a velocity dispersion image. If the 3rd image is not specified then fixed dispersion, sigma must be specified.
region
Region of image to be used. The default region is the entire image. See documentation on region for details. All pixels within the bounding box are used; pixel masking is not used.
sigma
Fixed value for z-dispersion if not specified by 3rd input image.
nchan
Number of channels for z-axis of output image. Default=1.
start
Starting value for z-axis of output image. No default.
step
Interval for z-axis of output image. No default.
out
The output (x,y,z) image. No default.
options
Options. Minimum match is active.
  relax  ignore axis descriptor mismatches
         (e.g. pixel increments etc).  Use with care.


 

Index

NAME
PERSON RESPONSIBLE
CATEGORIES
DESCRIPTION
PARAMETERS

This document was created by man2html, using the manual pages.
Time: 18:35:39 GMT, July 05, 2011