2.3.1.0 imager.setsdoptions

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imager.setsdoptions - Function

2.3.1 Set some options for single dish processing

Description

Various less-often-used options for single dish processing can be set.

scale: The overall scale of the single dish data is multiplied by this factor.
weight: The weight given to the single dish data in the imaging is multiplied by this factor.
convsupport: This parameter can be used to change the support used in gridding single dish data in imaging. If ’PB’ or ’pb’ is used as the ’convtype’ in setoptions this parameter is ignored as the support is defined by the primary beam. The deafult of -1 mans 1 as convsupport is used for ’box’ convolution function and 3 is used for ’SF’ convolution function.
pointingcolumntouse: This parameter is NOT to be changed under normal circumstances. This is to be used by those who know what they are doing and want to try to use different columns in the POINTING table especially if they believe their dish direction is wrong. And if any of the _OFFSET columns is used do not expect to be able to use a different frame in the image setup in defineimage. Possible values are DIRECTION, TARGET, ENCODER, POINTING_OFFSET, SOURCE_OFFSET
truncate: The truncation radius as a quantity or a float value. This parameter is effective only when ’GAUSS’ or ’GJINC’ is used as the ’convtype’ in setoptions. You can use an unit ’pixel’ to specify truncation radius as pixel value. If float value is set, or quantity without unit is set, its unit will be ’pixel’.
gwidth: The width of the gaussian beam as a radius of half maximum. This parameter is effective only when ’GAUSS’ or ’GJINC’ is used as the ’convtype’ in setoptions. You can use an unit ’pixel’ to specify truncation radius as pixel value. If float value is set, or quantity without unit is set, its unit will be ’pixel’. Note that, when ’GJINC’ is used as the ’convtype’, gwidth doesn’t directry specify width of the convolution function.
jwidth: The witdh of the jinc beam as a parameter c, where jinc = J_1(pi*x/c)/(pi*x/c). This parameter is effective only when ’GJINC’ is used as the ’convtype’ in setoptions. You can use an unit ’pixel’ to specify truncation radius as pixel value. If float value is set, or quantity without unit is set, its unit will be ’pixel’. Note that jwidth doesn’t directly specify width of the convolution function.

Arguments


Inputs
scale	Scaling applied to single dish data
	allowed:	double
	Default:	1.0
weight	Weights applied to single dish data
	allowed:	double
	Default:	1.0
convsupport	number of pixel for convolution support
	allowed:	int
	Default:	-1
pointingcolumntouse	Which Pointing Table column to use to get direction
	allowed:	string
	Default:	DIRECTION
truncate	truncation radius (effective only for ’GAUSS’ or ’GJINC’)
	allowed:	any
	Default:	variant -1pixel
gwidth	radius of half maximum for gaussian (effective only for ’GAUSS’ or ’GJINC’)
	allowed:	any
	Default:	variant -1pixel
jwidth	c-parameter for jinc function (effective only for ’GJINC’)
	allowed:	any
	Default:	variant -1pixel
minweight	Minimum weight level to use for weight correction and weight based masking.
	allowed:	double
	Default:	0.
clipminmax	Clip minimum and maximum values from each grid
	allowed:	bool
	Default:	false

Returns
bool

Example

- im.setsdoptions(scale=1.0, weight=1.0, convsupport=5)

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