Finding row index in a matrix in which the sum of the elements is greater than 1

I have the following matrix:

S=[1,0,0;0,1,0;1,1,0;0,1,1;0,0,1]

I want to find row indexes in which the sum of the elements is greater than 1.

How can I do this?

Thanks

Answer 1

[John D'Errico]

Just do EXACTLY what you said. I'll break it down into pieces.

S=[1,0,0;0,1,0;1,1,0;0,1,1;0,0,1]

S = 5×3

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

sum(S,2) % sum of the rows

ans = 5×1

1 1 2 2 1

sum(S,2) > 1 % testing if they exceed 1

ans = 5×1 logical array
   0
   0
   1
   1
   0

find(sum(S,2) > 1) % which rows satisfy that requirement?

ans = 2×1

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When you have a problem that is larger than your current abilities, break it into small, managable pieces. Solve each part, one at a time. Then put it all together. Eat a programming elephant one byte at a time.

Answer 2

[Mathieu NOE]

hello

here you are

S=[1,0,0;0,1,0;1,1,0;0,1,1;0,0,1]

S = 5×3

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

row_sum = sum(S,2);
rw_ind = find(row_sum>1)

rw_ind = 2×1

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