-
ndim_in
-
The number of dimensions in the input grid. This will be at
least one.
-
lbnd_in
-
Pointer to an array of integers, with "ndim_in" elements,
containing the coordinates of the centre of the first pixel
in the input grid along each dimension.
-
ubnd_in
-
Pointer to an array of integers, with "ndim_in" elements,
containing the coordinates of the centre of the last pixel in
the input grid along each dimension.
Note that "lbnd_in" and "ubnd_in" together define the shape,
size and coordinate system of the input grid in the same
way as they do in astResample
X
.
-
in
-
Pointer to an array, with one element for each pixel in the
input grid, containing the input data. This will be the same
array as was passed to astResample
X
via the "in" parameter.
The numerical type of this array should match that of the
data being processed.
-
in_var
-
Pointer to an optional second array with the same size and
type as the "in" array. If given, this will contain the set
of variance values associated with the input data and will be
the same array as was passed to astResample
X
via the
"in_var" parameter.
If no variance values are being processed, this will be a
NULL pointer.
-
npoint
-
The number of points at which the input grid is to be
interpolated. This will be at least one.
-
offset
-
Pointer to an array of integers with "npoint" elements. For
each interpolation point, this will contain the zero-based
index in the "out" (and "out_var") array(s) at which the
interpolated value (and its variance, if required) should be
stored. For example, the interpolated value for point number
"point" should be stored in "out[offset[point]]" (assuming
the index "point" is zero-based).
-
coords
-
An array of pointers to double, with "ndim_in"
elements. Element "coords[coord]" will point at the first
element of an array of double (with "npoint" elements) which
contains the values of coordinate number "coord" for each
interpolation point. The value of coordinate number "coord"
for interpolation point number "point" is therefore given by
"coords[coord][point]" (assuming both indices are
zero-based).
If any interpolation point has any of its coordinates equal
to the value AST__BAD (as defined in the "ast.h" header
file), then the corresponding output data (and variance)
should either be set to the value given by "badval",
or left unchanged, depending on whether the AST__NOBAD flag is
specified by "flags".
-
params
-
This will be a pointer to the same array as was given via the
"params" parameter of astResample
X
. You may use this to
pass any additional parameter values required by your
interpolation algorithm.
-
flags
-
This will be the same value as was given via the "flags"
parameter of astResample
X
. You may test this value to
provide additional control over the operation of your
resampling algorithm. Note that the special flag values
AST__URESAMP1, 2, 3 & 4 are reserved for you to use for your
own purposes and will not clash with other pre-defined flag
values (see astResample
X
).
-
badval
-
This will be the same value as was given via the "badval"
parameter of astResample
X
, and will have the same numerical
type as the data being processed (i.e. as elements of the
"in" array). It should be used to test for bad pixels in the
input grid (but only if the AST__USEBAD flag is set via the
"flags" parameter) and (unless the AST__NOBAD flag is set in
"flags") for identifying bad output values in
the "out" (and "out_var") array(s).
-
out
-
Pointer to an array with the same numerical type as the "in"
array, into which the interpolated data values should be
returned. Note that details of the storage order and number
of dimensions of this array are not required, since the
"offset" array contains all necessary information about where
each returned value should be stored.
In general, not all elements of this array (or the "out_var"
array below) may be used in any particular invocation of the
function. Those which are not used should be returned
unchanged.
-
out_var
-
Pointer to an optional array with the same type and size as
the "out" array, into which variance estimates for the
resampled values should be returned. This array will only be
given if the "in_var" array has also been given.
If given, it is addressed in exactly the same way (via the
"offset" array) as the "out" array. The values returned
should be estimates of the statistical variance of the
corresponding values in the "out" array, on the assumption
that all errors in input data values are statistically
independent and that their variance estimates may simply be
summed (with appropriate weighting factors).
If no output variance estimates are required, a NULL pointer
will be given.
-
nbad
-
Pointer to an int in which to return the number of interpolation
points at
which no valid interpolated value could be obtained. The maximum
value that should be returned is "npoint", and the minimum is
zero (indicating that all output values were successfully
obtained).