UNIX for Dummies Questions & Answers

Dear Unix Gurus,

I have a text file with multiple columns, for example, see sample.txt below

I want to find the maximum in, say, column 3, normalise all the values to this maximum value (to 4 decimal places) and spit everything into a new text file, i.e.

my problem is that while getting the maximum value is trivial, plugging this value back into the script (as an evironment variable?) to normalize the data is giving me a real headache. I first get the max value using

but I'm stuck on how to assign this value to an environment variable NORM such that

gives me the output that I want.

many thanks!

make sure to give the file name twice at the end as given in the below code

Code:

awk 'NR == FNR {if(max < $3) {max = $3}; next} {$3 = $3 / max}1' sample.txt sample.txt

If you want the formatting of 3rd field,

Code:

awk 'NR == FNR {if(max < $3) {max = $3}; next} {$3 = $3 / max; printf "%d\t%d\t%.04f\n", $1, $2, $3}' sample.txt sample.txt

works like a dream! Many thanks!