problem in writing a function

What is the problem with this code?

 function Y = BWMfn(B)
[m,n]=size(B);
Y=zeros(2*m,2*n);
for i=1:m;
 for   j=1:n;
    if B(i,j)<128
        Y(2*i-1,2*j-1)=0;
    else
        Y(2*i-1,2*j-1)=1;
    end
 end
end

BWM is a matrix. Please reply asap

[Bijoy]

I am getting this error:

Error using BWMfn (line 3)

Not enough input arguments.

Answer 1

[Image Analyst]

Why do you even want this anyway? It's kind of like simple thresholding

Y = B >= 128;

except that it has rows and columns of zeros interleaved. Why would you want that? By the way, you could vectorize it by doing:

Y = zeros(2*size(B));
Y(1:2:end, 1:2:end) = B >= 128;

[Bijoy]

I want the function in some other code for the purpose of data embeding. The function should do thresholding and give elements of the vector as Its output one by one. But the problem is I have to use the function within Some other loop.

Answer 2

[Walter Roberson]

You need to start the function from the command line, not by clicking on "Run" or pressing F5. For example at the command line command

BWMfn(rand(3,4))