Plot 3D - surface

Ok, the world is learning how to use Scilab. I like it a lot!

Now, let's make surfaces using the function plot3d(.).

This function is called like this: plot3d(x, y, z);

Where x and y are vectors and z is a matrix.

Look the example:


-->d = -3:3;

-->[x y] = meshgrid(d)
y =

- 3. - 3. - 3. - 3. - 3. - 3. - 3.
- 2. - 2. - 2. - 2. - 2. - 2. - 2.
- 1. - 1. - 1. - 1. - 1. - 1. - 1.
0. 0. 0. 0. 0. 0. 0.
1. 1. 1. 1. 1. 1. 1.
2. 2. 2. 2. 2. 2. 2.
3. 3. 3. 3. 3. 3. 3.
x =

- 3. - 2. - 1. 0. 1. 2. 3.
- 3. - 2. - 1. 0. 1. 2. 3.
- 3. - 2. - 1. 0. 1. 2. 3.
- 3. - 2. - 1. 0. 1. 2. 3.
- 3. - 2. - 1. 0. 1. 2. 3.
- 3. - 2. - 1. 0. 1. 2. 3.
- 3. - 2. - 1. 0. 1. 2. 3.

-->z = 9 - (x.^2 + y.^2);

-->plot3d(d, d, z);


The result is showed:


The coordinates x and y were the vector d (-3:3).

We can make any surface, so let's think in other surface. Look the next example:

-->x = -5:0.1:5;

-->y = 0:0.1:10;

-->[xc yc] = meshgrid(x, y);

-->w = %pi/4;

-->b = -0.5;

-->z = exp(b*yc).*sin(w*xc);

-->plot3d(x, y, z);


The result:


Try to make tests and generate surfaces.