Matrix, Mean coloum 2, with a value in coloum 1 < 25

Hello!

I am looking at a 5 x 2 matrix, which i need to mean certain numbers in the secound coloum. But the mean depends on what the value the first coloums has.

Here is the Matrix:

M = 

   25    0.1090
   23    0.0960
   15    0.5170
   40    0.9340
   35    0.1090

For all numbers in coloum 1 < 25, i need to mean the numbers in coloum 2

I have been searching this site for a long time after an answer, but found nothing.

I hope you can help me! :)

Thanks!

Answer 1

[Michael Haderlein]

just:

 mean(M(M(:,1)<25,2))

The keyword here is logical indexing, btw. You can find good tutorials about it online.

[Kasper Jørgensen]

Thanks, it's working just as intended! :)