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      Draw a box(es) or rectangle(s) of specified width


      Positions can be specified either by the cursor position or by
      supplying a vector of X,Y positions. By default, TVBOX now
    (since Jan 2012) assumes data coordinates if !X.crange is set.

Calling Sequence

      TVBOX, width, [ x, y, color, /DATA, ANGLE= ,COLOR =, _EXTRA = ]


      WIDTH - either a scalar giving the width of a box, or a 2 element
              vector giving the length and width of a rectangle.

Optional Inputs

      X - x position for box center, scalar or vector
      Y - y position for box center, scalar or vector. If vector, then Y
            must have the same number of elements as X
            Positions are specified in device coordinates unless /DATA is set
            If X and Y are not specified, and device has a cursor, then
            TVBOX will draw a box at current cursor position
      COLOR - String or integer specifying the color to draw the box(es)
            If COLORS is a scalar then all boxes are drawn with the same
            color value. Otherwise, the Nth box is drawn with the
            Nth value of color. Color can also be specified as
            string (e.g.'red'). See cgCOLOR for a list of available
            color names. Default = "opposite".



Optional Keyword Inputs

      ANGLE - numeric scalar specifying the clockwise rotation of
              the boxes or rectangles.
      COLOR - Scalar or vector, overrides the COLOR input parameter
              Color can be specified as a string (e.g. 'red') or intensity
              value. See cgCOLOR() for a list of color names.
              Default = 'opposite' (i.e. color opposite the background).
      /DATA - if this keyword is set and non-zero, then the box width and
              X,Y position center are interpreted as being in DATA
              coordinates. Note that data coordinates must be previously
              defined (with a PLOT or CONTOUR call). The default
              is to assume data coordinates if !X.CRANGE is set. Force
              device coordinates by setting DATA = 0 or /DEVICE
      /DEVICE Set this keyword to force use of device coordinates
      /FILL - If set, fill the box using cgCOLORFILL
      /SQUARE - If set, then a square is drawn, even if in data coordinates
              with unequal X and Y axes. The X width is used for the
              square width, and the Y width is ignored.
      Any keyword recognized by cgPLOTS (or cgCOLORFILL if /FILL is set)
      is also recognized by TVBOX.
      In particular, the linestyle, thickness and clipping of the boxes
      is controlled by the LINESTYLE, THICK and NOCLIP keywords.
      (Clipping is turned off by default, set NOCLIP=0 to activate it.)
      If /FILL is set then available keywords include LINE_FILL and

Side Effects

      A square or rectangle will be drawn on the device
      For best results WIDTH should be odd when using the default DEVICE
      coordinates. (If WIDTH is even, the actual size of the box will be
      WIDTH + 1, so that box remains centered.)


      (1) Draw a double thick box of width 13, centered at 221,256 in the
      currently active window
          IDL> tvbox, 13, 221, 256, thick=2
      (2) Overlay a "slit" with dimension 52" x 2" on a previously displayed
          image at a position angle (East of North) of 32 degrees. The
          slit is to be centered at XC, YC and the plate scale
          arcsec_per_pixel is known.
          IDL> w = [2.,52.]/arcsec_per_pixel ;Convert slit size to pixel units
          IDL> tvbox,w,XC,YC,ang=-32 ;Draw slit


        Allows use of only device (default) or data (if /DATA is set)
          coordinates. Normalized coordinates are not allowed

Procedures Used

      cgpolygon, zparcheck

Revison History

      Written, W. Landsman STX Co. 10-6-87
      Modified to take vector arguments. Greg Hennessy Mar 1991
      Fixed centering of odd width W. Landsman Sep. 1991
      Let the user specify COLOR=0, accept vector color, W. Landsman Nov. 1995
      Fixed typo in _EXTRA keyword W. Landsman August 1997
      Added ANGLE keyword W.Landsman February 2000
      Make sure ANGLE is a scalar W. Landsman September 2001
      Don't round coordinates if /DATA is set. M. Perrin August 2005
      Use STRICT_EXTRA to flag valid keywords W. Landsman Sep 2005
      Check that width has only 1 or 2 elements W. Landsman August 2010
      Use Coyote Graphcis W. Landsman February 2011
      Added /FILL keyword W. Landsman July 2011
      Default to data coordinates if !X.crange present WL Jan 2012
      Added Square keyword WL. April 2012

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