MATLAB: How to make this 3D plot from parameterized function

3d plots

Dear Sir:
Attached below is a picture from the textbook. Here is the function:
w=xy+z, x=cos(t), y=sin(t), z=t
The book shows the 3D plot of this function, which is a curve living in 3D. I am wondering how to do that in MatLab.
Next is a function:
w=x+2y+z^2, x=r/s, y=r^2+lns, z=2r
Since there are two parameters, so this function is a surface living in 3D. The book doesn't show the plot, but I wish I can plot it and take a look.
I have googled and just have no clue how to do this. I know some basice plotting, like contour, surface. I know how to plot a vector field. I am always eager to learn. If you can point me the direction, that will be great.
Thank you very much! Have a nice day!

Best Answer

success?
[r,s]=meshgrid(0:0.1:2);
x=r./s;  
y=r.^2+log(s);
z=2*r;
surf(x,y,z)
axis vis3d
Related Question