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Version 1.9 Build 1488

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coordsys.setdirection - Function

	Package	general
	Module	images
	Tool	coordsys

Set direction coordinate values

Synopsis
setdirection(refcode, proj, projpar, refpix, refval, incr, xform, poles)

Arguments

refcode	in	Reference code
		Allowed:	String
		Default:	No change
proj	in	Projection type
		Allowed:	String
		Default:	No change
projpar	in	Projection parameters
		Allowed:	Numeric vector
		Default:	No change
refpix	in	Reference pixel
		Allowed:	Numeric vector
		Default:	No change
refval	in	Reference value
		Allowed:	Vector of doubles, vector of quantities, quantity of vector of doubles, vector of string, record
		Default:	No change
incr	in	Increment
		Allowed:	Vector of doubles, vector of quantities, quantity of vector of doubles, vector of string, record
		Default:	No change
xform	in	Linear transform
		Allowed:	2-D numeric array
		Default:	No change
poles	in	Native poles
		Allowed:	Vector of doubles, vector of quantities, quantity of vector of doubles, vector of string, record
		Default:	No change

Returns
T or fail

Description

When you construct a Coordsys tool, if you include a Direction Coordinate, it will have some default parameters. This function simply allows you to replace the values of the Direction Coordinate.

You can also change almost all of those parameters (such as projection, reference value etc.) via the individual functions setreferencecode, setprojection, setreferencepixel, setreferencevalue, setincrement, and setlineartransform provided by the Coordsys tool. See those functions for more details about the formatting of the above function arguments.

Bear in mind, that if your Coordinate System came from a real image, then the reference pixel is special and you should not change it.

Example

- cs := coordsys(direction=T);
- cs.setdirection (refcode='GALACTIC', proj='SIN', projpar=[0,0],
                   refpix=[-10,20], refval="10deg -20deg");
- 
- cs.projection()
[type=SIN, parameters=[0 0] ] 
- cs.referencepixel()
[-10 20]  
- cs.referencevalue(format='s')
10.000000 deg -20.000000 deg