Create a PointList
A PointList object is a specialised type of Region which represents a collection of points in a coordinate Frame.
"
points"
array (which contains the point 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 "
npnt"
. "
[ncoord][dim]"
giving the
physical coordinates of the points. These should be stored such that the value
of coordinate number "
coord"
for point number "
pnt"
is found in element "
in[coord][pnt]"
. "
uncertainty"
Region so that it is centred at the point being
considered. The area covered by the shifted uncertainty Region then represents the
uncertainty in the position. The uncertainty is assumed to be the same for all
points.
If supplied, the uncertainty Region must be of a class for which all instances are centro-symetric (e.g. Box, Circle, Ellipse, etc.) or be a Prism containing centro-symetric component Regions. A deep copy of the supplied Region will be taken, so subsequent changes to the uncertainty Region using the supplied pointer will have no effect on the created Box. Alternatively, a NULL Object pointer may be supplied, in which case a default uncertainty is used equivalent to a box 1.0E-6 of the size of the bounding box of the PointList being created.
The uncertainty Region has two uses: 1) when the astOverlap function compares two Regions for equality the uncertainty Region is used to determine the tolerance on the comparison, and 2) when a Region is mapped into a different coordinate system and subsequently simplified (using astSimplify), the uncertainties are used to determine if the transformed boundary can be accurately represented by a specific shape of Region.
"
printf"
format specifiers identified by "
%"
symbols in the
normal way. "
options"
string contains "
%"
format specifiers,
then an optional list of additional arguments may follow it in order to supply
values to be substituted for these specifiers. The rules for supplying these are
identical to those for the astSet function (and for the C "
printf"
function). A null Object pointer (AST__NULL) will be returned if this function is invoked with the AST error status set, or if it should fail for any reason.
"
int
∗status"
.