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Creating a Dataset

Create a set of 32 irregularly-gridded data points in 3-D space that we can use as arguments to the TRIGRID and TRIANGULATE functions.

  1. Open a window for viewing:
    2. WINDOW

     

  2. Set SEED to the longword value 1. SEED is used to generate random points.
    3. SEED=1L

     

  3. Set the number of points to be randomly generated.
    4. N=32

     

  4. Create a set of X values for each of the 32 data points.
    5. X=RANDOMU(SEED,N)

     

  5. Create a set of Y values for each of the 32 data points.
    6. Y=RANDOMU(SEED,N)

     

  6. Create a set of Z values for each of the 32 data points from the X and Y values.
    7. Z=EXP(-3*((X-0.5)^2+(Y-0.5)^2))

     

  7. Plot the XY positions of the random points.
    8. PLOT,X,Y,PSYM=1,TITLE='Random XY Points'

     

    Figure 10-1: Plot of random values

    Figure 10-1: Plot of random values

     

  8. Dismiss the graphics window:
    9. WDELETE

  IDL Online Help (March 06, 2007)