CODEWITHSUNDEEP
matlaboctavevectorization
Arean
Arean

Reputation: 15

Is there a way to vectorize this code piece in matlab / octave?

Is there a way to vectorize this code piece?

for k=1:K
    vec_y(:,k) = y == k;
end

Here, y is a vector of 3000x1 dimension, and has elements 1 through 10 (representations) such that each representation has equal count as every other representation (i.e., there will be 300 counts of 1, 300 counts of 2, etc.).

What I want to do is rewrite or just create a new matrix that has the following binary representation for all occurrences of corresponding 1-10:

1 will be represented by [1;0;0;0;0;0;0;0;0;0], 2 will be [0;1;0;0;0;0;0;0;0;0], and so on.

I want to fully vectorize the code without using for loop.

Upvotes: 0

Views: 58

Answers (1)

Rafael Monteiro
Rafael Monteiro

Reputation: 4549

EDIT: as suggested by @Suever

One possibility:

% Sample y values
y = [1;9;5;6;3]

% Resulting matrix
m = bsxfun(@eq, 1:10, y)

m =

     1     0     0     0     0     0     0     0     0     0
     0     0     0     0     0     0     0     0     1     0
     0     0     0     0     1     0     0     0     0     0
     0     0     0     0     0     1     0     0     0     0
     0     0     1     0     0     0     0     0     0     0

Upvotes: 3

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