How do I do a logic check to see if one or more entries in an array is below a certain value?

I have a 2 column matrix, with the first column being dates and the second column being Fan Speed. I want to have a script search through the column and anytime it finds a fan speed below 8,000 it displays the date corresponding to from the first column. The fan speed is stored as Fan.data(:,2) and the dates are Fan.data(:,1). Can anyone help?

Answer 1

[Adam]

logicalIdx = Fan.data(:,2) < 8000;

dates = Fan.data(logicalIdx,1);