2.1.1.0 calibrater.modelfit

NRAO Home > CASA > CASA Toolkit Reference Manual

calibrater.modelfit - Function

2.1.1 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.

__________________________________________________________________

[next] [prev] [prev-tail] [front] [up]

More information about CASA may be found at the CASA web page

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