Transform N-dimensional coordinates

This function
applies a Mapping to transform the coordinates of a set of points in an arbitrary
number of dimensions. It is the appropriate routine to use if the coordinates are not
purely 1- or 2-dimensional and are stored in a single array (which they need not fill
completely).

If the coordinates are not stored in a single array, then the astTranP function might be more suitable.

void astTranN( AstMapping
$\ast $this,
int npoint, int ncoord_in, int indim, const double
$\ast $in, int forward, int ncoord_out,
int outdim, double $\ast $out
)

Pointer to the Mapping to be applied.

The number
of points to be transformed.

The number of coordinates being supplied
for each input point (i.e. the number of dimensions of the space in which the input
points reside).

The number of elements along the second dimension of the

`"`

in`"`

array (which contains the input coordinates). This value is required so that the
coordinate values can be correctly located if they do not entirely fill this array. The
value given should not be less than `"`

npoint`"`

. The address of the first
element in a 2-dimensional array of shape

`"`

[ncoord_in][indim]`"`

, containing
the coordinates of the input (untransformed) points. These should be stored
such that the value of coordinate number `"`

coord`"`

for input point number `"`

point`"`

is found in element `"`

in[coord][point]`"`

. A non-zero value
indicates that the Mapping

`’`

s forward coordinate transformation is to be applied,
while a zero value indicates that the inverse transformation should be used. The number of coordinates being generated by the Mapping for each output
point (i.e. the number of dimensions of the space in which the output points
reside). This need not be the same as

`"`

ncoord_in`"`

. The number of
elements along the second dimension of the

`"`

out`"`

array (which will contain the
output coordinates). This value is required so that the coordinate values can be
correctly located if they will not entirely fill this array. The value given
should not be less than `"`

npoint`"`

. The address of the first element
in a 2-dimensional array of shape

`"`

[ncoord_out][outdim]`"`

, into which the
coordinates of the output (transformed) points will be written. These will
be stored such that the value of coordinate number `"`

coord`"`

for output point
number `"`

point`"`

will be found in element `"`

out[coord][point]`"`

. If the number of points to be
transformed exceeds the largest value that can be represented by a 4-byte integer, then
the alternative

`"`

8-byte`"`

interface for this function should be used. This alternative
interface uses 8 byte integer arguments (instead of 4-byte). Specifically,
the arguments `"`

npoint`"`

, `"`

indim`"`

and `"`

outdim`"`

are changed from type `"`

int`"`

to type `"`

int64_t`"`

(defined in header file stdint.h). The function name is
changed by appending the digit `"`

8`"`

to the name. Thus, astTranN becomes astTranN8
Copyright (C) 2021 East Asian Observatory