How to plot 4D graph ?

I have two functions "f" and "g" and both are dependent on three variables being x,y and z. Both the functions and boundaries of x, y and z are provided as follows:

x = 150:5:250;
y = 0.2:0.05:0.3;
z = 1:0.1:2;
f = 20./(x.^0.2) .* (y.^0.3) .* (z.^0.01);
g = x .* y .* z

How can both the functions be plotted in one graph itself. Please help.

Answer 1

[Hugo]

You can use scatter3. To that end, you can create a matrix containing in each row the coordinates of each point and the value of f or g. Suppose the matrix is called M and the columns are the x, y, z values and the function. Then write:

   scatter3(M(:,1),M(:,2),M(:,3),5,'o',M(:,4))

and you will get each point with a different colour representing the value of f or g. Write:

   scatter3(M(:,1),M(:,2),M(:,3),M(:,4),'o')

and you will get each point with a different size representing the value of f or g. Write

   scatter3(M(:,1),M(:,2),M(:,3),M(:,4),'o',M(:,5))

and you will get the points with different sizes and different colours representing both f and g.

Whether it represents f and/or g depends on what you put in the columns 4 and 5.

Just in case, check the usage of scatter3 in the Matlab help. I might have messed up the order of the last inputs.

Hope this helps.