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Version 1.9 Build 1556

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qimager.fitpsf - Function

	Package	synthesis
	Module	qimager
	Tool	qimager

Fit the point spread function, making psf image first if needed

Synopsis
fitpsf(psf, bmaj, bmin, bpa, async)

Description
This fits an elliptical Gaussian to the point spread function and returns the fitted beam parameters. If psf image is not specified then a psf is made and used. The values for the beam fit are saved internally and used whenever needed (for example in the functions restore or smooth) until invalidated. The values are invalidated by setdata, setimage or any tool function that changes the weights. Use the function summary to check if there is a valid fitted psf stored internally.

Arguments

psf		Name of input psf
		Allowed:	String
bmaj		Major axis of beam
		Allowed:	Quantity record
bmin		Minor axis of beam
		Allowed:	Quantity record
bpa		Position angle of beam
		Allowed:	Quantity record
async		Run asynchronously in the background
		Allowed:	Bool
		Default:	!dowait

Returns
Bool

Example

- imgr.makeimage(type='psf', image='3C273XC1.psf')
- majaxis:=[=]; minaxis:=[=]; pangle:=[=]
- imgr.fitpsf('3C273XC1.psf', bmaj=majaxis, bmin=minaxis, bpa=pangle, async=F)
- print bmaj, bmin, bpa
- imgr.restore(model='bla' , complist='', image='bla.restored' , residual='bla2.residual' )

Or if one wants to generate a psf from the uv coverage and use that subsequently as in the following example:

- imgr.fitpsf(psf='')
- imgr.restore(model='bla' , complist='', image='bla.restored' , residual='bla2.residual' )