tdez3d

tdez3d uses Tdpack entries to draw an isosurface on a specified workstation.

Synopsis

    procedure tdez3d(
        wid[1]    : graphic,
        x[*]      : float,
        y[*]      : float,
        z[*]      : float,
        u[*][*][*]: float,
        value[1]  : float,
        rmult[1]  : float,
        theta[1]  : float,
        phi[1]    : float,
        ist[1]    : integer
    )

Arguments

wid

An NCL workstation identifier for where you want to draw your surface. The identifier wid is the value returned from an NCL call that created a workstation.

x

A 1-dimensional array specifying X-coordinate values.

y

A 1-dimensional array specifying X-coordinate values.

z

A 1-dimensional array specifying Z-coordinate values.

u

A 3-dimensional array specifying functional values at the X, Y, and Z coordinate values in the first three arguments. The values of u are stored with the first dimension varying the fastest, i.e. u(i,j,k) is the data value at (x(i),y(j),z(k)) for i=0, dimsizes(x), j=0,dimsizes(y), and k=0,dimsizes(z).

rmult, theta, phi

Values specifying an eye position (the point from which the isosurface will be viewed); these values are defined as follows:

• rmult is a multiplier of the diagonal length (DL) of the smallest box containing the surface to be drawn.
• theta is an angle (in degrees) in the XY plane measured positive counter-clockwise from the X axis
• phi is an angle (in degrees) measured from the positive Z axis toward the XY plane.

Thus, the coordinate (rmult*DL,theta,phi) is the spherical coordinate for the eye position. If rmult = theta = phi = 0., a default eye position ( 2.5,-55.,70.) is chosen.

The point looked at is calculated to be the midpoint of the box determined by the x, y, and z array limits.

ist

A style index defining the colors used to shade the isosurface. The legal values for ist are as follows:

ist	Description
1	produce a wire-frame surface
2	use gray shades underneath; gray shades on top
3	use gray shades underneath; red shades on top
4	use gray shades underneath; green shades on top
5	use gray shades underneath; blue shades on top
6	use gray shades underneath; cyan shades on top
7	use gray shades underneath; gray shades on top
8	use gray shades underneath; magenta shades on top

If ist is positive, then black is used for the background color and white for the foreground color; if ist is the negative of any of the above values, then white is used for the background color and black for the foreground color. If ist falls outside of the legal range, it is defaulted to 6.

Description

When tdez3d is called, a color table is defined for the workstation specified by wid in the first argument. This color table will supersede any color table that has been previously defined. The color table that is defined is:

Color index	Colors
0	black if IST is positive; white if IST is negative
1	white if IST is positive; black if IST is negative
2	red
3	green
4	blue
5	cyan
6	magenta
7	yellow
8-37	grayscale from white to black
38-67	shades of gray
68-97	shades of red
98-127	shades of green
128-157	shades of blue
158-187	shades of cyan
188-217	shades of magenta
218-247	shades of yellow

tdez3d does not call frame.

;
;  Create an X11 workstation.
;

      wid = create "tdez3d_example" xWorkstationClass defaultapp
        "wkPause" : True
      end create

;
;  Draw isosurface plot.
;
      tdez3d(wid, xo, yo, zo, u, 1., 0., 0., 0., 6)
      frame(wid)