Sgrayplot - smooth 2D plot of a surface using colors

Calling Sequence

Sgrayplot(x,y,z,<opt_args>)

Sgrayplot(x,y,z [,strf, rect, nax, zminmax, colminmax, mesh, colout])

Parameters

• x,y : real row vectors of size n1 and n2.
• z : real matrix of size (n1,n2). z(i,j) is the value of the surface at the point (x(i),y(j)).
• <opt_args> : This represents a sequence of statements key1=value1,key2=value2 ,... where key1 , key2,... can be one of the following: strf, rect, nax, zminmax, colminmax, mesh, colout (see plot2d for the 3 first and fec for the 4 last).
• strf,rect,nax : see plot2d .
• zminmax, colminmax, mesh, colout : see fec .

Description

Sgrayplot is the same as grayplot but the plot is smoothed. The function fec is used for smoothing. The surface is plotted assuming that it is linear on a set of triangles built from the grid (here with n1=5, n2=3):

             _____________
             | /| /| /| /|
             |/_|/_|/_|/_| 
             | /| /| /| /| 
             |/_|/_|/_|/_|

The function colorbar may be used to see the color scale.

The parameter zminmax is useful for animation purpose (see an example after) and the parameter colminmax lets the user choose a part of the current colormap (see the fec help page).

Enter the command Sgrayplot() to see a demo.

Examples

// example #1
x=-10:10; y=-10:10;m =rand(21,21);
clf()
xset("colormap",hotcolormap(64))
Sgrayplot(x,y,m, strf="011", rect=[-20,-20,20,20])

// example #2
t=-%pi:0.1:%pi; m=sin(t)'*cos(t);
clf()
xset("colormap",jetcolormap(64))
colorbar(-1,1)
Sgrayplot(t,t,m, strf="041")

// example #3: an animation display cos(t)*sin(x)sin(y).
// (Remark: this animation uses the old mode)
n = 30;
nt = 100;
x = linspace(0,2*%pi,n);
y = linspace(0,%pi,n/2);
z = sin(x')*sin(y);
t = linspace(0,4*%pi,nt);
xselect(); clf()
f=gcf();
f.color_map=jetcolormap(64);
f.pixmap='on';
colorbar(-1,1)
Sgrayplot(x,y,cos(t(1))*z, strf="042", zminmax=[-1,1])
c=gce(),e=c.children
xtitle("Kaa''s eyes")
for i = 1:nt
   e.data(:,3)=matrix(cos(t(i))*z,-1,1);
   show_pixmap()
end
f.pixmap='off';
  

See Also

fec ,   fgrayplot ,   grayplot ,   Sfgrayplot ,   colorbar ,  

Author

J.Ph.C.