Any unused space will be eliminated by the copying operation performed by this routine, so it may be used as a way of compressing NDF structures from which components have been deleted. This ability also makes NDFCOPY a useful alternative to SETBOUND in cases where an NDF’s size is to be reduced.
"Data" –- Each array component present is propagated to its counterpart.
"Variance" –- The VARIANCE component in the input NDF becomes the
DATA_ARRAY in the output NDF and retains its data type. The original DATA_ARRAY is not copied.
"Error" –- The square root of the VARIANCE component in the input NDF becomes the
DATA_ARRAY in the output NDF and retains the VARIANCE’s data type. The original
DATA_ARRAY and VARIANCE components are not copied.
"Quality" –- The QUALITY component in the input NDF becomes the
DATA_ARRAY in the output NDF and will be data type _UBYTE. The original DATA_ARRAY and VARIANCE components are not copied.
FALSE(the default), any NDFs contained within extensions of the input NDF are copied to equivalent places within the output NDF without change. If set
TRUE, then any extension NDFs which have the same bounds as the base input NDF are padded or trimmed as necessary in order to ensure that they have the same bounds as the output NDF.
TRUE, then the WCS bounds of the template supplied via Parameter LIKE are used to decide on the bounds of the output NDF. Otherwise, the pixel bounds of the template are used.
TRUE, then the number of pixel axes in the output NDF will be reduced if necessary to remove any pixel axes which span only a single pixel. For instance if
stokesis a three-dimensional data cube with pixel bounds (1:100,-50:40,1:3), and the Parameter IN is given the value
"stokes(„2)", then the dimensionality of the output depends on the setting of TRIM: if TRIM=
FALSEthe output is three-dimensional with pixel bounds (1:100,-50:40,2:2) and if TRIM=
TRUEthe output is two-dimensional with pixel bounds (1:100,-50:40). In this example, the third pixel axis spans only a single pixel and is consequently removed if TRIM=
TRUE, then the pixel bounds of the output NDF are trimmed to exclude any border of bad pixels within the input NDF. That is, the output NDF will be the smallest NDF that encloses all good data values in the input NDF.
TRUE. It controls the number of axes in the current WCS co-ordinate Frame of the output NDF. If TRIMWCS=
YES, then the current Frame in the output NDF will have the same number of axes as there are pixel axes in the output NDF. If this involves removing axes, then the axes to retain are specified by Parameter USEAXIS. If TRIMWCS=
NOthen all axes are retained in the current WCS Frame of the output NDF. Using the example in the description of the TRIM parameter, if the input NDF
stokeshas a three-dimensional current WCS Frame with axes (RA,Dec,Stokes) and TRIMWCS=YES, then an axis will be removed from the current Frame to make it two-dimensional (that is, to match the number of pixel axes remaining after the removal of insignificant pixel axes). The choice of which two axes to retain is controlled by Parameter USEAXIS. If, on the other hand, TRIMWCS was set to
FALSE, then the output NDF would still have two pixel axes, but the current WCS Frame would retain all three axes from the input NDF. If one or more current-Frame axes are removed, the transformation from the current Frame to pixel Frame may become undefined resulting in some WCS operations being unusable. The inverse of this transformation (from pixel Frame to current Frame) is unchanged however.
TRUEand some axes need to be removed from the current WCS Frame of the output NDF. It gives the axes which are to be retained in the current WCS Frame of the output NDF. Each axis can be specified using one of the following options.
An integer index of an axis within the current Frame of the input NDF (in the range 1 to the number of axes in the current Frame).
An axis Symbol string such as
A generic option where
"SPEC" requests the spectral axis,
"TIME" selects the time axis,
"SKYLAT" picks the sky longitude and latitude axes respectively. Only
those axis domains present are available as options.
The dynamic default selects the axes with the same indices as the pixel axes being
copied. The value should be given as a comma-separated list.
"Extracted section", which replaces the title derived from the input NDF.