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Next: image.coordmeasures - Function Up: image - Tool Previous: image.convolve2d - Function


image.coordsys - Function



Package general
Module images
Tool image


Get the Coordinate System of the image


Synopsis
coordsys(axes)


Arguments

axes in Axes to which the Coordinate System pertains
    Allowed: Vector of integers
    Default: All axes



Returns
coordsys tool or fail


Description

This function stores the Coordinate System of an image in a Coordsys tool.

By default, the Coordinate System describes all of the axes in the image. If you desire, you can select a subset of the axes, thus reducing the dimensionality of the Coordinate System. This may be useful if you are supplying a Coordinate System to the constructors imagefromarray or imagefromshape.



Example
- im := image('hcn')
- im.summary()
Image name       : hcn
Date observation : 2002/12/31/15:15:36
Image mask       : None
Image units      : JY/BEAM

Direction system : J2000
Frequency system : LSRK
Velocity  system : RADIO
Rest Frequency   : 1.414e+09 Hz

Name             Proj Shape Tile   Coord value at pixel    Coord incr Units
--------------------------------------------------------------------------- 
Right Ascension   SIN   155   31  17:42:29.303    90.00 -1.000000e+00 arcsec
Declination       SIN   178   30 -28.59.18.600    90.00  1.000000e+00 arcsec
Frequency               256   32  1.413350e+09     1.00  1.968717e+04 Hz
Velocity                          1.378053e+02     1.00 -4.174021e+00 km/s
-
-
- cs := im.coordsys([1,2])
- imshape := im.shape()[[1,2]]
- im2 := imagefromshape(outfile='test', shape=imshape, csys=cs)
- im2.summary()
Image name       : test
Image mask       : None
Direction system : J2000
Rest Frequency   : Absent

Name             Proj Shape Tile   Coord value at pixel    Coord incr Units
--------------------------------------------------------------------------- 
Right Ascension   SIN   155  155  17:42:29.303    90.00 -1.000000e+00 arcsec
Declination       SIN   178  178 -28.59.18.600    90.00  1.000000e+00 arcsec

In this example, we create a Coordinate System pertaining to the first two axes of the image and create a new (empty) 2D image with it with the imagefromshape constructor.





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