MATLAB: Is there a way to do the following without running a for loop.

indexing

clear all

y=randi(5,1,5)';

A=zeros(5,5);

for i=1:5,

A(i,y(i))=1;

end

I want to know if this can be implemented without using a for loop.

Best Answer

y = randi(5,1,5)'

Then

A = accumarray([(1:5)' y(:)], 1, [5 5]);

A = zeros(5,5);
A(sub2ind(size(A),1:5,y'))=1

Related Solutions

MATLAB: Change specific values in odd/even columns of a matrix

Try this:

A = [5     4     5     5
     5     1     5     3
     1     2     1     5
     5     3     5     1];
L = A == 1;
L(:,2:2:end) = false;
A(L) = 0

producing:

A =
     5     4     5     5
     5     1     5     3
     0     2     0     5
     5     3     5     1

MATLAB: How to make a for loop to select x number of column in a table. (WITHOUT having the same number multiple time)

Hi,

are you sure about having all possible combinations of 5 from 48? There are 1.712.304 possible combinations. You will find them by using the nchoosek function:

result = nchoosek(1:48,5)

This will give you all the combinations of 5 column numbers from 48 without repetations. You can use this result to index the corresponding columns.

Best regards

Stephan

Best Answer

Related Solutions

MATLAB: Change specific values in odd/even columns of a matrix

MATLAB: How to make a for loop to select x number of column in a table. (WITHOUT having the same number multiple time)

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