WELCOME TO THE MATRIX DEMO


   The Matrix demo visualizes a 3D data set in several
   different ways:


   o  Velocity field
      Each arrow represents a vector. This type of
      plot can be used to show ice displacement,
      slope gradient, oceanic current and more.

   o  Contour plot
      The lines connect data items with equal values.

   o  Image
      The X and Y coordinates correspond to the value
      indicated by the axes. The Z coordinate is
      represented by the color.

   o  Surface plot
      The data values are shown in perspective,
      giving a three dimensional view of the data set.

   o  Show3
      This combines 3 different representations
      of the same data set. The top has a contour
      plot. The bottom has an image plot. In the
      middle, there is a surface mesh.

      The plot is drawn with the simple command :

      SHOW3, data


   MENU OPTIONS
   ------------

   File Menu:
      Select "Quit" to exit the Matrix Demo and return
      to the IDL Demo Main Screen.

   About Menu:
      Select "About matrix plotting" for information 
      about the Matrix Demo.


   FEATURES
   --------
    Select one of the following from the set of 
    "radio buttons" to change the display:

    o  Velocity field
    o  Contour plot
    o  Image
    o  Surface
    o  Show3
    o  4 plots (items 1 through 4)
  

  <<Generate New Data button>>
    Click this button to generate and display a new
    data set.