MATLAB: In a large matrix, find and provide location of rows containing zeros

Question

I have a series of large matrix, 7184×72001, in which the first column is a datenum vector, and all the rows represent values for each datenum.

If a row didn't meet certain criteria, I asked my forloop to fill it with zeros. Unfortunately I didn't consider how large my matrix was and how hard it would then be to find the rows that contain zeros, if they exist. I know that in my first example, there is one row that is all zeros, excluding the datenum vector in the first column.

Is it possible to make a variable which contains the datenum value for the rows which contain zeros?

The following code, I have used to confirm that the row of zeros exist, but it doesn't tell me WHERE it is. Ideally I would get a list of datenums for the rows which are filled with zeros.

for row = 1 : size(Agoat, 1)
  zeroLocations{row} = find(Agoat(row, :) == 0)
end

Thank you everyone!

Answer 1

How about,

x=sum(Agoat(:,2:end),2);
Agoat(find(x==0),1);%answer matrix will contain all time stamps with zero rows.