3D Graphics
The world we live in is three dimensional (3D) and the computer screen
that we use in the labs is two dimensional (2D). There have been several
attempts to investigate alternative methods to represent phyical
situations on the flat screen of the computer screen.
Let's explore what the MATLAB
commands will do for us.
So we'll begin with some data that's easy to generate:
x = [0: pi/4: 6*pi];
y = [-pi/2: pi/16: pi/2];
z = y' * cos(x);
% why did i use y' above?
mesh(z)
title('Mesh Surface: f(x,y) = y cos(x)')
figure
[X,Y] = meshgrid(-8:.5:8); %create a matrix of (X,Y) from vector
R = sqrt(X.^2 + Y.^2) + eps; % sinc function sin(r)/r
Z = sin(R)./R;
mesh(X,Y,Z)
figure
mesh(x,y,z)
title('Mesh Surface: f(x,y) = y cos(x)')
xlabel('x'),ylabel('y'),zlabel('z')
figure
surf(z)
title('Shade Surface: f(x,y) = y cos(x)')
figure
contour(z)
title('Contour: f(x,y) = y cos(x)')
xlabel('x'), ylabel('y')
figure
meshc(z)
title('Mesh Surface with Contour: f(x,y) = y cos(x)
xlabel('x'), ylabel('y'), zlabel('z')
Within the MATLAB environment, it will be useful to explore
help hold % useful to plot another curve within current figure
[x,y,z] = peaks % predefined data set
contour (x,y,z,20,'k')
hold on
pcolor(x,y,z) % pseudocolor (checkerboard) plot
shading interp % default value is "faceted"
rotate3d on % your mouse can change azimuth and elevation - patience
figure
[c,h] = contour(peaks), clabel(c,h), colorbar % get picture with contours labeled and a color bar
figure
[x,y,z] = peaks % predefined data set
mesh(x,y,z)
view(-37.5,30)
view(0,0)
view(-90,0)
view(-37.5,10)