How do I select data from one vector based upon the values of another vector?

I am attempting to select data from a vector v() based upon another vector, s(). These vectors are already ordered based upon participant, i.e., the first element in vector v() and vector s() are from the same participant, the second element in both are from the same participant, etc.

Vector s() is a binary value (sex). I am attempting to select all participants who are male from vector v() to determine the mean of these data. How can I go about accomplishing this?

Answer 1

[jonas]

mean(v(s==true))

And false for the opposite gender

If you have more complex grouping data, then

G = findgroups(s)
splitapply(@mean, v, G)

Or put the data in a table and use grpstats

[Brian Hickman]

Worked- thank you!

[jonas]

cheers, please accept the answer formally :)