embedded if statement not working

I have a large CSV file used for data collection. The sensor data is recorded as long as the power is on. When the test is initiated, the value of a cell changes to 3. I have created a simple embedded if statement that seems to be missing the values. Any help would be appreciated. Thanks

untitled = <5561x129> double  %<---- Raw Data
a=1;
n=length(untitled);
for j=1:n
  if untitled(n,54) ==3;
    test_data(a,:)=untitled(n,:);
    a=a+1;
  end
end

but if I enter in the Command Window,

>> untitled(1680,54)
ans =
   3

Thanks

Answer 1

[the cyclist]

Guessing you want

if untitled(j,54) ==3;

instead of

if untitled(n,54) ==3;

Answer 2

[Chris]

Yep, Thanks

Answer 3

[Jan]

At first your code can be abbreviated:

index     = (untitled(:, 54) == 3);
test_data = untitled(index, :);

Now it has not been explained, why you think that something is missing. Is test_data empty after the code ran?

Is the value exactly 3 or is it 2.999999999999999, which is displayed as 3 in the command window? Please test this:

untitled(1680,54) - 3