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AST_MARK - Draw a set of markers for a Plot   

Description:
This routine 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.

Invocation:
CALL AST_MARK( THIS, NMARK, NCOORD, INDIM, IN, TYPE, STATUS )

Arguments:
THIS = INTEGER (Given)
Pointer to the Plot.
NMARK = INTEGER (Given)
The number of markers to draw. This may be zero, in which case nothing will be drawn.
NCOORD = INTEGER (Given)
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 = INTEGER (Given)
The number of elements along the first 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( INDIM, NCOORD ) = DOUBLE PRECISION (Given)
A 2-dimensional array 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(MARK,COORD).
TYPE = INTEGER (Given)
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.
STATUS = INTEGER (Given and Returned)
The global status.

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 AST_CLIP), 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
Next: AST_MATHMAP - Create a MathMap
Up: AST Routine Descriptions
Previous: AST_MAPBOX - Find a bounding box for a Mapping

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 210
R.F. Warren-Smith & D.S. Berry
30th April 2003
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2003 Central Laboratory of the Research Councils