How to calculate mean in AWK? line by line several files, thousands of lines

Shell Programming and Scripting
1

I'm kinda stuck on this one, I have 7 files with 30.000 lines/file like this

050	0.023	0.504336
050	0.024	0.529521
050	0.025	0.538908
050	0.026	0.537035

I want to find the mean line by line of the third column from the files named like this:

Stat-f-1.dat .... Stat-f-7.dat 
Stat-s-1.dat .... Stat-s-7.dat
2

Calculate the mean of third column in awk:

awk '{x+=$3;next}END{print x/NR}' data

Now, do you want the mean from values of each files separately?
Or all Stat-f* files together, then all Stat-s*...?

3

I wanted the average line by line, 1st line of all files print average in a new file, 2nd line, and so on...

4

not tested....

awk '{x[FNR]+=$3;next}END{for(i=1;i in x;i++) print x/ARGC}' allMyFilesWildWildCard
1 Like
5

file 1

001     0.046   0.667267
001     0.047   0.672028
001     0.048   0.656025
001     0.049   0.660557

002     0.000   0.669553
002     0.001   0.594648
002     0.002   0.586738
002     0.003   0.593728
002     0.004   0.593658

File 2

001     0.046   0.654565
001     0.047   0.665057
001     0.048   0.660074
001     0.049   0.670424

002     0.000   0.669462
002     0.001   0.594793
002     0.002   0.589329
002     0.003   0.593949
002     0.004   0.592371

They are seven (7) files

Desired Output

001     0.046   Average of the nth line from the two files
001     0.047   Average of the nth line from the two files
001     0.048   Average of the nth line from the two files
001     0.049   Average of the nth line from the two files

002     0.000   Average of the nth line from the two files
002     0.001   Average of the nth line from the two files
002     0.002   Average of the nth line from the two files
002     0.003   Average of the nth line from the two files
002     0.004   Average of the nth line from the two files

Thanks for your help!! Can you try on those files?

The filenames are like Stat-zz.dat, zz goes from 00 to 07

6

I'll let you do the honors and let us know how it goes!
Good luck!

7

@vgersh99: you need to divide by (ARGC-1)

@AriasFco: try this:

$ awk '{
  avg[$1,$2]+=$3; 
  i[FNR]=$1 SUBSEP $2
}
END{
  for(k in i) sorted_i[j++]=k+0; 
  n=asort(i,sorted_i); 
  for(j=1; j<=n; j++) 
    print i[j]"\t" avg[i[j]]/(ARGC-2)
}' SUBSEP='\t' Stat-f-*.dat
2 Likes
8

ok, a little change:

awk '{x[FNR]+=$3;next}END{for(i=1;i in x;i++) print x/(ARGC-1)}' Stat-0[0-7].dat
9

yep, just noted that myself - thanks for the catch!