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astMark - Draw a set of markers for a Plot

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).


next up previous 264
Next: astMaskX - Mask a region of a data grid
Up: AST Function Descriptions
Previous: astMapType - Get the data type of an entry in a KeyMap

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
25th February 2013
E-mail:starlink@jiscmail.ac.uk

Copyright (C) 2014 Science \& Technology Facilities Council