casa6

<casaxml xsi:schemaLocation="http://casa.nrao.edu/schema/casa.xsd file:///opt/casa/code/xmlcasa/xml/casa.xsd" xmlns="http://casa.nrao.edu/schema/psetTypes.html" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

​

​

​

​

​

<task type="function" name="imtrans" category="analysis">

​

<shortdescription>Reorder image axes</shortdescription>

​

<input>

    <param type="path" name="imagename" mustexist="true"><shortdescription>Name of the input image which must be specified.</shortdescription><description>Name of the input image which must be specified.</description>

            <value/>

        <example>imagename='ngc5921.im'</example>

    </param>

​

    <param type="string" name="outfile"><shortdescription>Name of output CASA image.</shortdescription><description>Name of output CASA image.</description>

        <value/>

        <example>outfile='reordered.im'</example>

    </param>

    <param type="any" name="order"><shortdescription>New zero-based axes order.</shortdescription><description>New zero-based axes order.</description>

        <any type="variant" limittype="string stringArray int"/>

        <value type="string"/>

        <example>order=&quot;120&quot;</example>

        <example>order=120</example>

        <example>order=[&quot;d&quot;, &quot;f&quot;, &quot;r&quot;]</example>

    </param>

</input>

<returns type="bool"/>

​

<example>

PARAMETER SUMMARY

imagename        Name of the input image

outfile          Name of output CASA image. Must be specified.

order            Output axes mapping

​

This task reorders (transposes) the axes in the input image to the specified

order. The associated pixel values and coordinate system are transposed.

​

The order parameter describes the mapping of the input axes to the output axes.

It can be one of three types: a non-negative integer, a string, or a list of

strings. If a string or non-negative integer, it should contain

zero-based digits describing the new order of the input axes. It must

contain the same number of (unique) digits as the number of input axes. For example,

specifying order="1032" or order=1032 for a four axes image maps input axes

1, 0, 3, 2 to output axes 0, 1, 2, 3. In the case of order being a nonnegative integer

and the zeroth axis in the input being mapped to zeroth axis in the output, the zeroth

digit is implicitly understood to be 0 so that to transpose an image where one would

use a string order="0321", one could equivalently specify an int order=321.

IMPORTANT: When specifying a non-negative integer and mapping the zeroth axis of

the input to the zeroth axis of the output, do *not* explicitly specify the leading

0; eg, specify order=321 rather than order=0321. Python interprets an integer with

a leading 0 as an octal number.

​

Because of ambiguity for axes numbers greater than nine, using string or integer order

specifications cannot handle images containing more than 10 axes.

The order parameter can also be specified as a list of strings which uniquely match,

ignoring case, the first characters of the image axis names (ia.coordsys().names()).

So to reorder an image with right ascension, declination, and frequency axes, one could

specify order=["d", "f", "r"] or equivalently ["decl", "frequ", "right a"]. Note that

specifying "ra" for the right ascension axis will result in an error because "ra" does

not match the first two characters of "right ascension".

Axes can be simultaneously inverted in cases where order is a string or an array of

strings by specifying negative signs in front of the axis/axes to be inverted. So,

in a 4-D image, order="-10-3-2" maps input axes 1, 0, 3, 2 to output axes 0, 1, 2, 3 

and reverses the direction and values of input axes 1, 3, and 2.   

EXAMPLE: 

# Swap the stokes and spectral axes in an RA-Dec-Stokes-Frequency image

imagename = "myim.im"

outfile = "outim.im"

order = "0132"

imtrans()

​

# or

​

outfile = "myim_2.im"

order = 132

imtrans()

​

# or

​

outfile = "myim_3.im"

order = ["r", "d", "f", "s"]

imtrans()

​

# or

​

utfile = "myim_4.im"

order = ["rig", "declin", "frequ", "stok"]

imtrans()

​

</example>

​

</task>

​

</casaxml>