Plotting A Matrix Using Surfc

Hello--

I am struggling an recieivng an error when I try to plot a matrix using surfc (in a function). I was wondering if anybody knew why.

My input for N is 10.

function lake = MakeLake_BDP(N)
lake = zeros(N,N);
lake(1,:) = -999;
lake(N,:) = -999;
lake(:,1) = -999;
lake(:,N) = -999;
%randn where the dist has a mean of 4 and sd of 2
lake(2:N-1,2:N-1) = 4 + 2.*randn(N-2);

T = lake;
w = .175; %weighing factor
for k = 1:15
    T(1,:,k+1) = -999;
    T(N,:,k+1) = -999;
    T(:,1,k+1) = -999;
    T(:,N,k+1) = -999;
    for i = 2:N-1
        for j = 2:N-1
            [open] = Isopen(i,j,N);
            M = sum(open);
            T(i,j,k+1) = T(i,j,k)*(1-w)+w/M*([T(i-1,j,k),T(i+1,j,k),T(i,j-1,k),T(i,j+1,k)]*open);
        end
    end
end
lake = T; %sets lake equal to T
%plotting
surfc(lake);


end
function [open] = Isopen(row,col,N)
%initialize open
open = ones(4,1);
%row and col values/concention for directions
%if statement
if row == 2
    open(1,1) = 0; %up
elseif row == N-1
    open(2,1) = 0; %down
elseif col == 2
    open(3,1) = 0; %left   
elseif col == N-1
    open(4,1) = 0; %right 
end
end

Answer 1

[Walter Roberson]

Your T is created as 3 dimensional. You are trying to surfc() a 3D volume. surfc() and surf() are only for 2D arrays (on a plane that might be warped.)

You can use isosurface() or you can use slice(). Or you can use the volumeViewer() app. Or you can use vol3d v2 from the File Exchange.

[Brian Peoples]

My homerwork says:

1. Plot the surface of ​lake​ using a 3-D contour plot. Comment on how it looks at the bottom of your main function before your subfunction. Use the ​surfc​ function to make this plot.

Are you sure this cannot be used?

[Walter Roberson]

I am certain that you cannot use surfc() to plot all of T in one call.

What I do not know is what relationship T has to the surface of a lake.

For example I could hypothesize that T(:,:,end) might represent the surface of a lake, and that you might surfc() that .