Replacing whole row with NaN's if first value is equal to 13 or 15.

Hi! I have a matrix in which I want to replace the whole row with NaNs if the value of the first row is equal to 13 of 15. Can anyone help me with this?

Answer 1

[Voss]

Do you mean the value of the first column is equal to 13 or 15?

A = randi(20,10,5)

A = 10×5

1 1 3 2 20 15 14 17 19 10 14 14 11 19 9 1 9 1 4 18 4 8 2 16 19 19 17 10 4 19 11 1 20 5 1 13 1 6 14 9 8 7 13 10 14 12 9 8 7 4

idx = A(:,1) == 13 | A(:,1) == 15;
A(idx,:) = NaN

A = 10×5

1 1 3 2 20 NaN NaN NaN NaN NaN 14 14 11 19 9 1 9 1 4 18 4 8 2 16 19 19 17 10 4 19 11 1 20 5 1 NaN NaN NaN NaN NaN 8 7 13 10 14 12 9 8 7 4

Or do you mean replace the whole column if the value of the first row is 13 or 15?

A = randi(20,10,5)

A = 10×5

18 13 10 1 6 8 15 5 7 18 13 4 12 18 3 2 17 6 17 10 6 16 8 10 15 3 11 13 14 7 12 2 13 14 8 13 20 15 1 2 12 4 11 6 18 11 15 1 11 11

idx = A(1,:) == 13 | A(1,:) == 15;
A(:,idx) = NaN

A = 10×5

18 NaN 10 1 6 8 NaN 5 7 18 13 NaN 12 18 3 2 NaN 6 17 10 6 NaN 8 10 15 3 NaN 13 14 7 12 NaN 13 14 8 13 NaN 15 1 2 12 NaN 11 6 18 11 NaN 1 11 11

[MadjeKoe]

Thank you so much! I meant the first thing!

[Voss]

You're welcome!