Locating the largest number and performing division

Shell Programming and Scripting
1

I have a tab delimited file with the following format

1 r 109 45 3 5 6 7
2 f  300 249 5 8 10
3 g 120 4 5 110 0
4 t 400 300 250 0 0
.....
.....
100,000 lines

I would like to get the largest number in columns 4, 5, 6, 7, 8 and divide that largest number with the number in column 3.

Desired output

1 r 109 45 3 5 6 7 0.41
2 f  300 249 5 8 10 0.83
3 g 120 4 5 110 0 0.9166
4 t 400 300 250 0 0 0.75

I tried excel today this but since it has over 100,000 lines, it is difficult to do it. Please let me know the best way to do it awk or see.

2 
awk '{ for(N=3; N<=8; N++) if((A[N] == "") || (A[N]<$N)) A[N]=$N }
END {
        for(N=4; N<=8; N++) printf("%f / %f = %f\n", A[N], A[3], A[N]/A[3]);
}' inputfile
3

I guess this is what you want:

awk '{max=""; for (i=4; i<=NF; i++) if ($i>max) max=$i; print $0, max/$3}' file
1 r 109 45 3 5 6 7 0.412844
2 f  300 249 5 8 10 0.83
3 g 120 4 5 110 0 0.916667
4 t 400 300 250 0 0 0.75
1 Like
4

I wanted to print an output file as a tab delimited file. I tried the following:

 awk -F $ '\t' '{ print $1,$2,$3,$4+$5,$6,$7,$8,$9;}' inputfile > outputfile.txt

But the output is not tab delimited. Let me know

5

Read about the OFS variable in your AWK manual page.

Regards,
Alister