PERMAXES - Permute an NDF's pixel axes

Description:

This application re-orders the pixel axes of an NDF , together with all related information (AXIS structures, and the axes of all co-ordinate Frames  stored in the WCS  component of the NDF).

Usage:

permaxes in out perm

Parameters:

IN = NDF (Read)

The input NDF data structure.

OUT = NDF (Write)

The output NDF data structure.

PERM() = _INTEGER (Read)

A list of integers defining how the pixel axes are to be permuted. The list must contain one element for each pixel axis in the NDF. The first element is the index of the pixel axis within the input NDF which is to become Axis 1 in the output NDF. The second element is the index of the pixel axis within the input NDF which is to become Axis 2 in the output NDF, etc. Axes are numbered from 1.

TITLE = LITERAL (Read)

A title for the output NDF. A null value will cause the title of the NDF supplied for Parameter IN to be used instead. [!]

Examples:

permaxes a b [2,1]

Swaps the axes in the two-dimensional NDF called a, to produce a new two-dimensional NDF called b.

permaxes a b [3,1,2]

Creates a new three-dimensional NDF called b in which Axis 1 corresponds to Axis 3 in the input three-dimensional NDF called a, Axis 2 corresponds to input Axis 1, Axis 3 corresponds to input Axis 2.

Notes:

• If any WCS co-ordinate Frame has more axes then the number of pixel axes in the NDF, then the high numbered surplus axes in the WCS Frame are left unchanged.

• If any WCS co-ordinate Frame has fewer axes then the number of pixel axes in the NDF, then the Frame is left unchanged if the specified permutation would change any of the high numbered surplus pixel axes. A warning message is issued if this occurs.

Related Applications :

KAPPA: ROTATE, FLIP; FIGARO: IREVX, IREVY, IROT90.

Implementation Status:

• This routine correctly processes the AXIS, DATA, QUALITY, VARIANCE, LABEL, TITLE, UNITS, WCS, and HISTORY  components of the input NDF and propagates all extensions.

• Processing of bad pixels and automatic quality masking are supported.

• All non-complex numeric data types can be handled. The data type of the input pixels is preserved in the output NDF.