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ccdsub - sub/average of an image, and optionally reorder axes.


ccdsub [parameter=value]


ccdsub takes a subimage from an image, as described by a new set of coordinates in X, Y and/or Z (since the expression of the selected axes is arbitrary, the resulting coordinate system may be bogus).

Since cubes/images produced by this program may have dummy axes (length 1), you will need to use ccdslice(1NEMO) to get rid of them, or use the dummy= keyword below.

If no parameters are given, other than in= and out=, the image is copied straight through, which is still a great way to test your I/O subsystem, assuming your image fits in memory.


The following parameters are recognized in any order if the keyword is also given:
Input image file
Output image file
X coordinates to select. Valid numbers are 1..nx. By default all will be selected. See also centerbox below.
Y coordinates to select. Valid numbers are 1..ny. By default all will be selected.
Z coordinates to select. Valid numbers are By default all will be selected.
Number X to aver (size remains same)
Number Y to aver (size remains same)
Number Y to aver (size remains same)
Up to three values (between 0 and 1) to take that fraction of that axis for subsetting the cube. Using this option will override the corresponding x=, y= and/or z=. Any axis not specified will inherit the corresponding x=, y= or z=. Default: not used.
Write out dummy axes as well? [true]
New order of axes after all previous actions have been taken. The default is no reordering, i.e. keep it in xyz order. To reverse only the X and Y axis, reorder=yxz is needed.


To reorder a cube from xyz to zxy and back to xyz, the 2nd step will have a perhaps non-intuitive axis reordering, since it refers to the new "zxy" order:
    ccdsub cube0 - reorder=zxy | ccdsub - cube1 reorder=yzx

See Also

ccdslice(1NEMO) , ccdmom(1NEMO) , image(5NEMO)


Peter Teuben

Update History

1993         code written         PJT
22-Feb-97    man page written    PJT
12-aug-02    more doc    PJT
17-jun-03    WCS for simple subsetting    PJT
9-apr-09    V1.6 replace skip= with dummy=, fix bug nzaver=      PJT
18-jun-09    V2.0a fixed bug when Z size if different from XY    PJT
24-dec-2020    V2.4  add centerbox=    PJT

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