Average in awk

Shell Programming and Scripting
1

Hi

I am looking for an awk script which can compute average of all the fields every 5th line. The file looks:
A B C D E F G H I J K L M
1 18 13 14 12 14 13 11 12 12 15 15 15
2 17 17 13 13 13 12 12 11 12 14 15 14
3 16 16 12 12 12 11 11 12 11 16 14 13
4 15 15 11 11 11 12 11 12 11 15 14 16
5 14 14 10 12 11 12 11 13 12 14 16 16
6 13 13 11 11 13 11 10 12 12 14 15 15
7 12 12 27 24 12 12 11 11 15 16 15 14
8 12 11 26 23 11 13 11 12 14 15 15 14
9 12 11 25 22 11 12 11 11 13 14 15 14
10 15 12 24 21 11 12 10 13 13 15 16 14

I need to compute the average of the individual fields (A to M) for every 5th line (line 1 to 5: 6-10 etc).
I greatly appreciate any help.
Thanks

2 
awk '{
  for (i=1; i<=NF; i++) {
    s+=$i
    c++
    }
  }1    
NR > 1 && !(++_ % 5) {
  printf "avg: %.2f\n", s/c
  s=c=""
  }' file

Use nawk or /usr/xpg4/bin/awk on Solaris.

3

No better than Radoulov:

(NR%5)!=0 {
        for (i=1; i<=NF; i++){
                sum+=$i
        }
}
(NR%5)==0 {
        for (i=1; i<=NF; i++) printf "%d ", sum/5
        printf "\n\n"
        delete sum
}

On gawk.

4

I think I misread the question ...

5

... or me?

6

The OP wants

so your approach seams correct.
I'm not sure, perhaps it should be columns, instead of fileds.

It's compatible with GNU Awk and POSIX Awk (/usr/xpg4/bin/awk on Solaris).

But if the first line contains column headers, you should not use the NR variable, but something like this:

{
        for (i=1; i<=NF; i++){
                sum+=$i
        }
}
NR>1 && !(++c%5) {
        for (i=1; i<=NF; i++) printf "%d ", sum/5
        printf "\n\n"
        delete sum
}

Or including the input lines (and making it compatible with some nawk versions):

awk '{ for (i=1; i<=NF; i++) sum+=$i } 1
NR > 1 && !(++_%5) {
        printf "\navg:\n"
        for (i=1; i<=NF; i++) printf "%d ", sum/5
        printf "\n\n"
        split("", sum)
}' file
7

thank you all for the help. will try and let you know.