Copies an NDF (or NDF section) to a new location
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.
["Data"]
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. [FALSE]
[!]
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.
[FALSE]
[!]
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 stokes
is 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=FALSE
the output
is three-dimensional with pixel bounds (1:100,-50:40,2:2) and if TRIM=TRUE
the
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
. [FALSE]
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. [FALSE]
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=NO
then
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 stokes
has 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. [TRUE]
TRUE
and 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 "RA"
or "VRAD"
.
A generic option where "SPEC"
requests the spectral axis, "TIME"
selects the time axis,
"SKYLON"
and "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.