This chapter shows how to display graphic representations of three-dimensional data. The two main procedures for doing this are CONTOUR and SURFACE. Procedures for displaying data as an image, another type of three-dimensional data representation, are discussed in Chapter 6: Displaying Images. The 3D plotting procedures include:

; Draws contour plots.

CONTOUR, z [, x, y] 

; Draws contour plots.

CONTOUR2, z [, x, y] 

; Draws 3D surface plots.

SURFACE, z [, x, y] 

; Draws shaded 3D surface plots.

SHADE_SURF, z [, x, y] 

CONTOUR, CONTOUR2, and SURFACE use line graphics to depict the value of a two-dimensional array. As their names imply, CONTOUR and CONTOUR2 draw contour plots. SURFACE depicts the surface created by interpreting each array element as an elevation. SURFACE projects this three-dimensional surface, after an arbitrary rotation about the x– and z–axis, into two dimensions. It then connects each point with its neighbors using hidden line removal.

Almost all of the information concerning coordinate systems, keyword parameters, and system variables that are discussed in Chapter 4: Displaying 2D Data, also apply to CONTOUR, CONTOUR2, and SURFACE.