Here are a couple of useful things that MATLAB can do with 2D plots:

• filled polygons with text

  Source Code	Source Code

• pie chart

  
  

  
  % pie chart code
  a= [5 10 15 20 25 30 35 40];
  pullout = [0 0 0 1 0 0 0 0 ];
  pie(a,pullout); % pull out one of the slices
  title('Sohie''s Sample Pie Chart');
  
  

• error bars

  
  

  
  x = linspace(0,2,21);
  % erf is a built-in special MATLAB function:
  %  erf(x) = 2/sqrt(pi) * integral from 0 to x of exp(-t^2) dt.
   
  y = erf(x);
  e = rand(size(x))/10;
  
  errorbar(x,y,e)
  title ('Sample Error Bar plot');
  

• Other specialized 2D graphs (check out via MATLAB's help)

  area - Filled area plot

  bar - Bar graph

  barh - Horizontal bar graph

  bar3 - 3D bar graph

  comet - Comet-like trajectory

  ezplot - Easy to use function plotter

  feather - Feather plot

  fplot - Plot functions

  hist - Histograms

  pie3 - 3D pie chart

  plotmatrix - Scatter plot matrix

  ribbon - Draw 2D lines as ribbons in 3D

  stem - Discrete sequence or "stem" plot

  stairs - Stairstep plot

What about 3D plots?

For line plotting, use plot3 rather than plot, as shown below.

t = 0:pi/50:5*pi;
plot3(sin(t),cos(t),t);
grid on;

Sometimes it is useful to plot 3D surfaces.
Here is an example of a simple mathematical equation.

        z = x² - y²

How to plot this equation:

1. Create two datapoint series. Say -10<=x<=10 and -8<=y<=8.
   
2. Create two new vectors that contain the squares of the x and y vectors from Step 1.
   
3. Use meshgrid to create matrices of all the x squared and y squared values in proper orientation.
   

   The effect of meshgrid is to create a matrix X with the x-values along each row, and a matrix Y with the y-values along each column. This is done so that it is easy to evaluate a function z=f(x,y) of two variables on the rectangular grid. Click here for an example of how meshgrid works.

4. Create the matrix Z in terms of X and Y (where Z(i,j) = X(i)^2 - Y(j)^2)
   
   • Plot the mesh and/or the surface of Z.

     mesh(Z); % looks like fishing net
     

   • surf(Z); % shows surface in color
     

   • contour(Z); % shows contour plot
colorbar; % with colorbar
     

Here are some fun 3D plots:

Source Code

Here is code for other fun 3D plots:

• torus
• snowcone

• Other specialized 3D graphs (check out via MATLAB's help)

  comet3 - 3D comet-like trajectories

  meshc - Combination mesh/contour plot

  meshz - 3D mesh with curtain

  stem3 - 3D stem plot

  quiver3 - 3D quiver plot

  slice - Volumetric slice plot

  surfc - Combination surf/contour plot

  trisurf - Triangular surface plot

  trimesh - Triangular mesh plot

  waterfall - Waterfall plot