UNIX for Dummies Questions & Answers

Hi,

For each row in a file, i would like to identify the maximum value and calculate the percentage/fraction of the max for other values in the row.
Then, I would like to print a copy of the file where values above a threshold are replaced with "1" and other values are left as "0".
In the example below, the threshold is >=0.25 (25%)

Any notes on commands much appreciated!

Thank you!!

input file:
9,0,30,0
0,50,100,20
0,10,0,0
10,100,0,50

## fraction of max value##
0.3,0,1,0
0,0.5,1,0.2
0,1,0,0
0.1,1,0,0.5

Therefore, request output (ony assign "1" if >=0.25):
1,0,1,0
0,1,1,0
0,1,0,0
0,1,0,1

Hi, this should do it.

Code:

awk -F, '{m=0; for (i=1;i<=NF;i++) if ($i>m) m=$i; for (i=1;i<=NF;i++) {s=(i==NF)?RS:FS; if($i>=0.25*m) printf 1s; else printf 0s}}' infile

Just out of curiousity, what is this for? This isn't homework, is it?

Thanks!!
No, this isn't homework. I'm actually a unix-naive scientist and I have some huge genetic data files which I'm trying to convert into more manageable files which I can analyse in R. I'm more familiar with R but it's a lot slower than unix for enormous data sets... I've ordered unix in a nutshell which will hopefully help with my problems - most of which i've noticed seem to need a good understanding of how to handle arrays.
Thanks again