# Logical comparison (>= to be specific) between each element (row) of a column vector, and all elements inside each row of a matrix having same number or rows, respectively

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Jonathan Morcos on 25 Nov 2020
Commented: Jonathan Morcos on 25 Nov 2020
I am wondering if there is a better/faster way to do this, perhaps without a for loop?
Say, I have a 30x50 matrix A, and a 30x1 column vector B. I want to procuce a 30x50 logical matrix C, where each element of C is 1 if the corresponding element of A is greater than or equal to the element of B located on the same row as that element.
For a small example:
>> A = [1 2 3 4 5 6; 7 8 9 10 11 12; 13 14 15 16 17 18];
B = [4 10 16]';
%numbers are in ascending order to simplify example
C = false(3,6);
c = 1;
for k = B'
C(c,:) = (A(c,:) >= k);
c = c + 1;
end
The output:
C
C =
3×6 logical array
0 0 0 1 1 1
0 0 0 1 1 1
0 0 0 1 1 1

Stephen Cobeldick on 25 Nov 2020
Edited: Stephen Cobeldick on 25 Nov 2020
A = [1,2,3,4,5,6;7,8,9,10,11,12;13,14,15,16,17,18]
A = 3×6
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
B = [4;10;16]
B = 3×1
4 10 16
C = A>=B % requires >=R2016b
C = 3x6 logical array
0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1
C = bsxfun(@ge,A,B) % for earlier versions
C = 3x6 logical array
0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 1 1 1

#### 1 Comment

Jonathan Morcos on 25 Nov 2020
Wow, I feel quite silly. I don't know why I didn't think that would work. Thank You!