Select matrix rows based on criteria

I have a 1000 rows by 100 column matrix. i) wish to select those rows which meet a criteria, and then use this to select the equivalent position from a second column vector. I tried to produce a column vector where if any element i n a row met or exceeded the criteria then I would get a 1 (or 0 if not). Then i planned to use this 'mask' to select from the second vector.# My problems:

criteria = >10.6 mask=(data(:))>=10.6;

returns an empty matrix. What am I missing? is there a simple way.[The second column vector could be included in the original data but must not be part of the elements evaluated against the criteria] Thanks in advance

Answer 1

[Matt Tearle]

I can't quite work out the code (maybe the formatting is confusing me), but it sounds like what you're trying to do is this:

A = magic(4)
y = (14:17)'
threshold = 13;

idx = any(A > threshold,2);
y(idx)

This selects the rows of A that contain any value greater than 13, then extracts those rows of the 4-element column vector y.