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tdez2d

Draws a surface on the specified workstation.

Prototype

	procedure tdez2d (
		wks   [1] : graphic,  
		x     [*] : float,    
		y     [*] : float,    
		z  [*][*] : float,    
		rmult [1] : float,    
		theta [1] : float,    
		phi   [1] : float,    
		ist   [1] : integer   
	)

Arguments

wks

An NCL workstation identifier for where you want to draw the surface. The wks identifier is one returned either from calling gsn_open_wks or calling create to create a Workstation object.

x

A one-dimensional array specifying X-coordinate values; must be monotonically increasing.

y

A one-dimensional array specifying Y-coordinate values; must be monotonically increasing.

z

A two-dimensional array specifying functional values at the X and Y coordinate values in the first two arguments. The values of z are stored with the first dimension varying the fastest, i.e. z(i,j) is the data value at (x(i),y(j)) for i=0, dimsizes(x)-1 and j=0,dimsizes(y)-1.

rmult
theta
phi

Values specifying an eye position (the point from which the surface 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 surface.

ist

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

istDescription
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 defaults to 6.

Description

This function draws a surface on the specified workstation, using the low-level package, Tdpack. When tdez2d is called, a color table is defined for the workstation specified by wks. This color table will supersede any color table that has been previously defined. The color table that is defined is:

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

tdez2d does not call frame.

See Also

Initialization routines: tdinit, tdpara, tdclrs

Parameter access routines: tdgetp, tdgtrs, tdsetp, tdstrs

Point transforming routines: tdprpt, tdprpa, tdprpi

Line drawing routines: tdline, tdlndp, tdlnpa, tdlpdp, tdcurv, tdcudp

Grid drawing routines: tdgrds, tdgrid

Label drawing routines: tdlbls, tdlbla, tdlblp, tdplch

Surface drawing routines: tddtri, tdstri, tditri, tdmtri, tdttri, tdctri, tdotri, tdsort

Simplified interface routines: tdez3d

Examples

The following code produces a sample surface plot:

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"

begin

;
;  Create the input arrays.
;
  nxi = 11
  nyi = 17

  xi = fspan(0.,1.,nxi)
  yi = fspan(0.,1.,nyi)
  zi = new((/nxi,nyi/),float)
  zi = 0.5 + 0.25 * (sin(-7.*conform(zi,xi,0)) + cos(5.*conform(zi,yi,1)))

;
;  Set up the output grid.
;
  nxo = 31
  nyo = 21
  xo = fspan(0.,1.,nxo)
  yo = fspan(0.,1.,nyo)

;
;  Interpolate.
;
  zo = ftsurf(xi,yi,zi,xo,yo)

  wks = gsn_open_wks("x11","test")
;
;  Draw plot.
;
  rho   = 3.
  theta = 36.
  phi   = 67.

  tdez2d(wks, xo, yo, zo, rho, theta, phi, -6)
  frame(wks)
end