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calibrater.modelfit - Function

2.2.1 Model fitting
Description

This method fits single-component models (points, elliptical Gaussians or elliptical Disks_ to the CORRECTED_DATA of the selected field. A first guess for the component parameters may be specified in the par parameter.

Arguments





Inputs

vary

If specified where T, let this parameter (in par) vary in fit

allowed:

boolArray

Default:

niter

Number of non-linear fitting iterations

allowed:

int

Default:

0

compshape

Component shape, P=point G=gaussian

allowed:

string

Default:

P

par

Initial guess for fit parameters (default is for ”P)”I flux, rel RA, rel Dec, 1,0, 0.0, 0.0 are defaults

allowed:

doubleArray

Default:

1.0 0.0 0.0

file

If specified, output componentslist file name, if empty don’t write componentslist file

allowed:

string

Default:

Returns
doubleArray

Example

cb.open(’ngc5921.ms’);  
cb.selectvis(field=’1331*’)  
cb.modelfit(compshape=’P’,par=[15.0,0.0,0.0])  
cb.close();

This example fits a point source mode using 15.0 Jy at the origin (phase center) as a first guess.

cb.open(’ngc5921.ms’);  
cb.selectvis(field=’1331*’)  
cb.modelfit(compshape=’G’,par=[15.0,0.0,0.0,2.0,1.0,0.0])  
cb.close();

This example fits a Guassian model with a starting guess of 15 Jy at the phase center (0,0), with 2.0 arcsec major axis, 1.0 axial ratio, at position angle 0.0 deg.

Please send any comments or questions about CASA or AIPS++ to aips2-requests@nrao.edu

Copyright © 2008 Associated Universities Inc., Washington, D.C.

This code is available under the terms of the GNU General Public Lincense


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