# coyote: CGMAPVECTOR__DEFINE

- coyote/Graphics
- coyote/Map Projections
- [Source code]

Description

      This object allows vectors (arrows) to be placed as annotations on map
      projections created with the cgMap coordinate object.

Categories

      Graphics, Map Projections

Author

      FANNING SOFTWARE CONSULTING::
         David W. Fanning
         1645 Sheely Drive
         Fort Collins, CO 80526 USA
         Phone: 970-221-0438
         E-mail: david@idlcoyote.com
         Coyote's Guide to IDL Programming: http://www.idlcoyote.com

History

      Change History::
         Written by David W. Fanning, 21 November 2011.
         Tested and bugs fixed. 17 Sept 2012. DWF.
         Bug fix in draw method when passing lat/lon vectors. 6 Jan 2013. DWF.
         Added PALETTE keyword to allow the vectors to be drawn in colors scaled
            to vector magnitude. 6 Jan 2012. DWF.
         The CLIP keyword was not working correctly and was fixed 29 April 2013. DWF.

Copyright

      Copyright (c) 2011, Fanning Software Consulting, Inc.
      e initialization method for the object.

Params

      class: out, optional, type=structure
         Occasionally, it is useful to have an object class definition as
         a structure variable. Using this output keyword will allow that.

Keywords

      addcmd: in, optional, type=boolean, default=0
         If this keyword is set, the object is added to the resizeable graphics
         window, cgWindow. The DRAW method of the object is called in cgWindow.
      clip: in, optional, type=fltarr(4)
         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 cgMap object.
      color: in, optional, type=string, default="opposite"
         The name of the color to draw the grid lines in.
      hsize: in, optional, type=float, default=0.35
         The value of this keyword sets the length of the arrowhead. See the documenation
         for the ARROW command ind IDL for further explanation.
      lats: in, optional, type=float
         The latitude values where the vector is to be drawn.
      length, in, optional, type=float
         The U and V vectors are mutiplied by LENGTH before they are used
         to calculate the (x1,y1) endpoint of the vector. By default, the length is set
         to 1/100th of the XRANGE of the MapCoord object. This means that the maximum
         length of a vector will be approximately LENGTH * SQRT(2).
      linestyle: out, optional, type=integer, default=1
         Set this keyword to the type of linestyle desired. See Graphics Keywords in
         the on-line help for additional information.
      lons: in, optional, type=float
         The longitude values where the vector is to be drawn.
      noclip: in, optional, type=boolean, default=0
         Set this keyword to supress clipping of the plot.
      mapcoord: in, optional, type=object
         The map coordinate for the object.
      palette: in, optional, type=byte
         A (256x3) color palette containing the RGB color vectors to use for coloring the vectors
         according to the magitude of the vectors. If the color palette is not 256 colors in length
         then the magitude is scaled into the number of colors available. If a color palette is
         used, then the `Color` keyword is ignored.
      solid: in, optional, type=boolean, default=0
         Set this keyword to draw solid arrow heads.
      t3d: in, optional, type=boolean, default=0
         Set this graphics keyword if you wish to draw using the T3D transformation matrix.
      thick: in, optional, type=integer, default=1
         Set this keyword to the thickness of the line used to draw the grid.
      umagnitude: in, optional, type=float
         The magnitude of the vector in the U direction.
      uvcoords: in, optional, type=boolean, default=0
         Set this keyword if the LONS and LATS are specified in UV (XY) coordinates, rather than
         longitude and latitude coordinates.
      vmagnitude: in, optional, type=float
         The magnitude of the vector in the V direction.
      zvalue: in, optional, type=float, default=0.0
         Set this keyword to the ZVALUE where the output should be drawn.
      _extra: in, optional
         Any keywords appropriate for superclass objects are also permitted.
      is is the clean-up routine for the object.
      is is the class definition module.