How do I remove every row that has a zero in it?

I have a 366x7 matrix, and I'm trying to remove each row that has a zero in it, I would prefer to use for loops instead of some built-in function.

so for example

TSLA = rand(366,7)

for col = 1:1:size(TSLA,1)

if TSLA(col,4) == 0

TSLA(col,:) = []

end

end

for whatever reason it removes like 61 rows, but leaves like 20 or so with zeros.

Then it says "Index in position 1 exceeds array bounds. Index must not exceed 305." Even though the initial matrix is 366...

Answer 1

[John D'Errico]

TSLA = rand(366,7);

TSLA(TSLA(:,4) == 0,:) = [];

One line. No loops.

[Rocco]

Awesome, worked perfectly, I was trying to do something similar in my testing where I searched for all the rows with 0 in them but I couldn't figure out how, thank you!

Answer 2

[Image Analyst]

Try this:

% Check which rows have a zero in one or more columns:
zeroRows = any(TSLA == 0, 2); % Logical index.  Equals true if a zero in the row, false if no zero in the row.
% Delete those rows:
TSLA(zeroRows, :) = []; % Delete the row by setting all column values of the row to null.

[Rocco]

Thank you! I've seen similar answers from you in different posts, however I've been trying to avoid using any because for whatever reason my professor doesn't want me to. I really appreciate the comments on the side though, they help understanding a lot!

[Image Analyst]

OK, just be aware that the answer you accepted does not "remove every row that has a zero in it" like you asked for. It only removes the row if there is a zero in column 4. The other columns are not checked like in my answer.

OK, since this was a homework problem, and your professor told you explicitly not to use anyone's code other than your own, you should not use John's or my answer or you could get into trouble. I will tag the question as homework, since you forgot. Normally when the student tags it as homework we know not to give complete solutions so the student won't get into trouble.

What you should do is like you tried originally but you need to check all the columns, not just column 4, like this:

if TSLA(col, 1) == 0 || TSLA(col,2) == 0 || etc.

[Rocco]

I should've given more context, the reason I'm only checking column 4 is because columns 4-7 will all be 0 if column 4 is a 0, the problem is a stock readout for a given day and month.

Furthermore, my professor allows me to have help as long as I cite it, for example we're allowed to go into the MATLAB forums etc. I have asked him about this before, and he said it's alright.