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imager.setscales - Function

2.3.1 Set the scale sizes for MultiScale Clean


Description

The multiscale clean algorithm cleans an image on a number of different scales, decomposing the image into Gaussians of these scale sizes. This function allows the user to set the number of scales used (using the nscales method), or to directly control the sizes of the scales in pixels (using the uservector method). When using the nscales method, the scales are calculated using the following formula:

θminor10.0(i-Nxscales∕2)∕2.0
(2.3)

where θmin is the fitted minor axis of the clean beam. The first value is zero.

Arguments





Inputs

scalemethod

Method by which scales are set

allowed:

string

Default:

nscales

uservector

nscales

nscales

Number of scales

allowed:

int

Default:

5

uservector

Vector of scale sizes in pixels to use, defaults should be 0,3,10

allowed:

doubleArray

Default:

0.0 3.0 10.0

Returns
bool

Example

 
 
- im.setscales(scalemethod=’nscales’, nscales=6);  
 
Here we make six scales automatically using the method described  
above.  
Or we could manually choose the scales in pixel numbers as follows:  
 
- im.setscales(scalemethod=’uservector’, uservector=[0,3,10,30]);  
 
 
Note: 0 pixel is the delta function, so if one were to select scale 0 only  
it would be  equivalent to a Hogbom clean.  
 

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