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A Library for Handling
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Description:
This function draws a
set of markers (symbols) at positions specified in the physical coordinate system of a
Plot. The positions are transformed into graphical coordinates to determine where the
markers should appear within the plotting area.
Synopsis
void astMark( AstPlot
this, int nmark, int ncoord,
int indim, const double in,
int type )
Parameters:
this
Pointer to the Plot.
nmark
The number of markers
to draw. This may be zero, in which case nothing will be drawn.
ncoord
The number
of coordinates being supplied for each mark (i.e. the number of axes in the current
Frame of the Plot, as given by its
Naxes attribute).
indim
The number of
elements along the second dimension of the " in" array (which contains the
marker 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 " nmark" .
in
The address of the first element of a
2-dimensional array of shape " [ncoord][indim]" giving the physical coordinates of the
points where markers are to be drawn. These should be stored such that the
value of coordinate number " coord" for input mark number " mark" is found in
element " in[coord][mark]" .
type
A value specifying the type (e.g. shape)
of marker to be drawn. The set of values which may be used (and the shapes
that will result) is determined by the underlying graphics system.
Notes:
-
Markers are not drawn at positions which have any coordinate equal to the value
AST__BAD (or where the transformation into graphical coordinates yields coordinates
containing the value AST__BAD).
-
If any marker position is clipped (see astClip), then the entire marker is not
drawn.
-
An error results if the base Frame of the Plot is not 2-dimensional.
-
An error also results if the transformation between the current and base Frames of
the Plot is not defined (i.e. the Plot’ s TranInverse attribute is zero).
Copyright (C) 2021 East Asian Observatory
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- AST
A Library for Handling
World
Coordinate Systems
in Astronomy - Next→
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