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coordsys.increment - Function

	Package	general
	Module	images
	Tool	coordsys

Recover the increments

Synopsis
increment(format, type)

Arguments

format	in	Format string
		Allowed:	String from combination of "n", "q", "s", "m"
		Default:	'n'
type	in	Coordinate type
		Allowed:	String from "direction", "stokes", "spectral", "linear", "tabular" or unset
		Default:	All

Returns
Vector of doubles, vector of quantities, vector of string, record or fail

Description

Each axis associated with the Coordinate System has a reference value, reference pixel and an increment (per pixel). These are used in the mapping from pixel to world coordinate.

This function (short-hand name i) returns the increment (in world axis order). You can recover the increments either for all coordinates (leave type unset) or for a specific coordinate type (mimumum match of the allowed types will do). If you ask for a non-existent coordinate an exception is generated.

See the discussion regarding the formatting possibilities available via argument format.

You can set the increment with function setincrement.

Example

- cs := coordsys(direction=T, spectral=T)
- cs.increment(format='q')
[__*0=[value=-1, unit='], __*1=[value=1, unit='], __*2=[value=1000, unit=Hz]] 
-
- cs.increment(format='n')
[-1 1 1000]  
-
- cs.increment(format='n', type='spectral')
1000