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Harris Geospatial / Docs Center / Libraries / Coyote / FSC_COLORBAR__DEFINE




      Note: The name of the routine has been changed from COLORBAR__DEFINE
      on 25 Sept 2010 to avoid conflicts with an IDL 8.0 routine of the
      same name. See the article "IDL 8 Name Conflicts" here:


      The purpose of this routine is to implement a FSC_COLORBAR object
      class. The ColorBar is rendered in the direct graphics system.


      David Fanning, Ph.D.
      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



Calling Sequence

      colorbar = Obj_New("FSC_COLORBAR")


      All inputs to the program are via keyword parameters.

Keyword Parameters

  Background: Background color. This is the color with which the colorbar is
              erased. The default color is !P.Background.
  Bottom: Bottom color index of colors allocated to colorbar.
  Charsize: Character size of annotation. Default is 1.0.
  Color: Color of annotation and outline. Default is !P.Color.
  Font: Font to use for annotation. Default is -1, Hershey fonts.
  Format: Format of annotation. Default is "(F8.2)".
  Major: The number of major tick intervals. Default is 5.
  Minor: The number of minor tick intervals. Default is 2.
  MinusOne: Set this keyword to choose MinusOne keyword on the Congrid command
              that resizes the colorbar into the window.
  NColors: The number of colors allocated to colorbar. Default is (256 <
  Neighbor: Set to indicate Nearest Neighbor sampling for Congrid. Default is
            0 (Bilinear).
  Position: The position of colorbar in normalized coordinates. Default for a
            horizontal colorbar is [0.15, 0.88, 0.85, 0.95]. Default for a
            vertical colorbar is [0.88, 0.15, 0.95, 0.85]. These defaults are
            designed for a 400 by 400 window.
  Range: The data range on colorbar. Default is [0, 255].
  TickLen: The length of tick marks. Default is -0.1
  TickV: Locations for the tick marks in data units. This is the same as
            the [XY]TickV keyword. Default is to do what IDL would do
  Vertical: Set this keyword if you want a vertical colorbar. Default is
  XEraseBox: A five-element vector of X points (normalized) for erasing the
              colorbar plot. Normally this keyword will not have to be used.
              The program uses the plot REGION for erasing. But larger
              character sizes can result in annotation going outside the
              region enclosed by the plot. If that is the case, then use this
              keyword along with YEraseBox to specify a larger-than-normal
              erasure area. The points are sent to the POLYFILL command for
                POLYFILL, xEraseBox, yEraseBox, /Normal, Color=background
  YEraseBox: A five-element vector of Y points (normalized) for erasing the
              colorbar plot.
  Clamp: This procedure method allows the color bar range to be "clamped"
          to a particular data range.
  Draw: This procedure method draws the colorbar in the display window. The
        ERASE keyword to this method will erase the current colorbar (by
        calling the ERASE method) before drawing the colorbar in the display
  Erase: This procedure method erases the colorbar object in the window. It
          accomplishes this by performing a POLYFILL in the background color.
          This method is primarily useful for interactive graphics display
  GetProperty: This procedure method allows one to obtain the current state
                of the object via the keyword parameters listed above.
              colorbar->GetProperty, Range=currentRange, Title=currentTitle
              Print, currentRange, currentTitle
  SetProperty: This procedure method allows one to set the properties of the
                colorbar object via the keywords described above. In addition,
                a DRAW and ERASE keyword are provided so that the colorbar can
                be immediately drawn when the new property is set.
              colorbar->SetProperty, Range=[500, 15000], /Erase, /Draw

Common Blocks


Side Effects

      The display window is not erased first.




      To create a colorbar, use it, then destroy it, type:
      colorbar = Obj_New("FSC_COLORBAR", Title='Colorbar Values', Range=[0,1000],$
      LoadCT, 5
      colorbar->SetProperty, Range=[0,500], /Erase, /Draw
      Obj_Destroy, colorbar

Modification History

      Written by: David Fanning, Fanning Software Consulting,
                  26 November 1998.
      Added Horizontal keyword to SetProperty method and fixed problem in
      going from Vertical to Horizontal color bars. 29 Nov 1998. DWF.
      Added LoadCT method and current color table index to object.
            6 December 1998.
      Fixed a bug dealing with nearest neighbor resampling. 30 Mar 1999. DWF.
      Fixed a bug with how NCOLORS and BOTTOM keywords interacted.
            29 Aug 1999. DWF.
      10 Oct 99. Modified the program so that current plot and map coordinates
                are saved and restored after the colorbar is drawn. DWF.
      26 May 2000 Added {XY}TICKV capability to the draw method. This
                required adding TickV to the object data structure, and to the
                INIT, GetProperty and SetProperty methods.
                Changed default tick length to -0.1. DWF (and Jack Saba)
      18 Nov 2001. Added Clamp method. DWF.
      25 September 2010. Renamed to FSC_Colorbar__Define to avoid conflict with a
                Colorbar__Define program introduced with IDL 8.0. DWF.

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