for loops not working

The below code is to calculate the modes on a plate. The for loops are not using all the values of m & n

% Modes on a plate
Lx=0.286; % length of plate(m)
Lz=0.198; % breadth of plate(m)
for m = 1:1000 % mode numbers
  for n = 1:10
    func=((n.*pi)./Lx).^2 +((m.*pi)./Lz).^2;% summation function n=1:10 & m= 1:1000
  end
end

[dpb]

I'm sure the loop runs 10,000 times--only you don't do anything inside the loop except write over the same variable with each computed value in succession so all you get in the end is the very last value.

[sriram amarnath]

So how do i get a matrix of every value?

Answer 1

[madhan ravi]

The same goal can be achieved trivially using meshgrid() or ndgrid() without a loop:

% Modes on a plate
Lx=0.286; % length of plate(m)
Lz=0.198; % breadth of plate(m)
n=10;
m=1000;
[Y,X]= ndgrid(1:m,1:n);
func=(X*pi/Lx).^2 +(Y*pi/Lz).^2;

But the modication in your code is as follows:

func = zeros(1000,10); % before loop
func(m,n) = ... %just add (m,n) next to func inside the loop

[sriram amarnath]

Thanks madhan ravi your a saviour!

Answer 2

[dpb]

"The MATLAB way" is to avoid the loops altogether...

N=10; M=1000;
[X,Y]=meshgrid([1:N],1:M]);
func=(X*pi/Lx).^2 +(Y*pi/Lz).^2;