Surf() Question

I'm trying to plot the results from an ethernet simulation, but I'm getting an error when I reach the surf() command. Everything else seems to be correct in the code.

Here is how I call the function:

%outputs 
U=(frame_cntr.*10)./10000;
wt=find(waiting_time ~= -1);
ave_wait=sum(wt)./frame_cntr;

[n,p]=meshgrid(N,P);
surf(n,p,U)
surf(n,p,ave_wait)

and here is the error I'm getting:

??? Error using ==> surf at 70
Z must be a matrix, not a scalar or vector.

Error in ==> Telecomm_Main at 157
surf(n,p,U)

Any help is appreciated!

Answer 1

[Wayne King]

 U=(frame_cntr.*10)./10000;

The above must be a vector, but in order to use surf(), this must be a matrix.

For example:

Z = randn(100,1);
surf(Z)

Will generate the exact error you are getting.

If you want a 3-D plot of a vector, you can use plot3()

Answer 2

[Walter Roberson]

You have not shown us any definition for N or P, so we have no idea what their sizes are relative to U. You have not given us any size hints for frame_cntr so we are not able to figure out the size of U (which would be the same as the size of frame_cntr).

Are you sure that frame_cntr is not a scalar when you run? frame_cntr would have to be a 2D matrix for everything else to work out dimensionally .

[Paloma]

Yeah I double checked and my U and average_wait time are coming out as scalars, so I've gotta figure out where that is going wrong.

Thanks!