MAP_PLOTS__DEFINE Name
MAP_PLOTS__DEFINE
Purpose
This object is a wrapper for the PLOTS routine in IDL. It provides a simple
way to draw polygons or lines on images which use a MAPCOORD object to set up the map
projection space. A map coordinate space must be in effect at the time the
Draw method of this object is used.
Author
FANNING SOFTWARE CONSULTING
David Fanning, Ph.D.
1645 Sheely Drive
Fort Collins, CO 80526 USA
Phone: 970-221-0438
E-mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com
Category
Graphics Calling Sequence
mapCoordObj = Obj_New('MapCoord', 'Lambert Azimuthal', CENTER_LAT=90, CENTER_LON=0)
plotObject = Obj_New('Map_PlotS', lons, lats, mapCoordObj)
mapCoordObj -> Draw
plotObject -> Draw
Auguments
lons: A vector (or scalar) of longitude values to plot.
lats: A vector (or scalar) of latitude values to plot.
mapCoordObj: A map coordinate object which can return a map structure for converting coordinates
from lon/lat coordinates to XY coordinates. Typically, a MAPCOORD object. An
alternative way of specifying a map coordinate object is to use the MAP_OBJECT
keyword. But don't do both. Note, this object is *not* destroyed when the MAP_PLOTS
object is destroyed. You are responsible for destroying the map coordinate object.
A map coordinate object is REQUIRED. So, if you don't specify a this argument, use the
MAP_OBJECT keyword to pass this object into the program.
Keywords
All of the following INIT keywords can be set and obtained using the SETPROPERTY and GETPROPERTY methods.
CLIP: The coordinates of a rectangle used to clip the graphics output.
The rectangle is specified as a vector of the form [X0, Y0, X1, Y1],
giving coordinates of the lower left and upper right corners,
respectively. The default clipping rectangle is the plot window set
up by the MAPCOORD object.
COLOR: The name of the color to draw the lines or symbols in. Default: "white".
LINESTYLE: Set this keyword to the type of linestyle desired. See Graphics Keywords in
the on-line help for additional information. Default is 0, solid line.
MAP_OBJECT: A MAPCOORD object or equivalent which had the ability to provide a map
structure with a GetMapStructure method. Don't use this keyword if you have
passed a map coordinate object as a positional parameter.
NOCLIP: Set this keyword to supress clipping of the plot. Set to 0 by default.
PARENT: An object reference to an object that will be the parent of this object.
PSYM: The plotting symbol to use for the plot. Can use any symbol available in
the Coyote Library routine cgSYMCAT. Set to 0 by default.
SYMSIZE: Set this keyword to the size of symbols. Default is 1.0.
T3D: Set this graphics keyword if you wish to draw using the T3D transformation matrix.
THICK: The thickness of the lines. Set to 1.0 by default.
ZVALUE: Set this keyword to the ZVALUE where the output should be drawn. Set to 0 by default.
UVCOORDS: Set this keyword if the LONS and LATS are specified in UV (XY) coordinates, rather than
longitude and latitude coordinates.
Dependencies
The following programs (at least) are required from the Coyote Library:
http://www.idlcoyote.com/programs/error_message.pro
http://www.idlcoyote.com/programs/cgcolor.pro
http://www.idlcoyote.com/programs/cgsymcat.pro
Modification History
Written by David W. Fanning, 9 January 2009.
Added MAP_OBJECT keyword and depreciated MAP_STRUCTURE keyword. 30 May 2009. DWF.
Fixed a problem in setting MAP_OBJECT in SetProperty method. 12 June 2009. DWF.
Fixed a problem with converting lat/lon to UV coordinates in the DRAW method. 13 June 2009. DWF.
Circular parent references when passed a MAP_OBJECT was fixed, preventing memory
leakage. 30 August 2009. DWF.
Removed the MAP_STRUCTURE keyword, which caused MASSIVE problems and added a mapCoordObj
parameter. 9 November 2009. DWF.