Help with awk loop

Question

[Francisco Muñoz]

Hi everyone! I'm new to awk and i'm having troubles with a script i thought would be easier. I have a variable number of columns with numbers (e.g. 4.45), and some of the "cells" have missing values (--). I have to calculate the mean of each row, adding a new column with it. I tried something like:

awk 'BEGIN {FS=";";OFS=";";SUM=0;AVG=0;MSS=0};
NR==1 {print $0,"Average","Missing"};
NR>1 {for (i=4;i<=NF;i++) {if ($i!="--") SUM+=$i};print $0,$SUM; SUM=0}' $FILE

In that example i'm not calculating the mean but just the sum as a test, but the results are senseless. I also have to add a "Missing" column where i count the missing values of each row. What am i doing wrong? Thanks in advance!

[Francisco Muñoz]

Thank you all! The error was in the use of $ as kloetzl stated

Answer 1

[kloetzl]

Don't prefix any variables in awk with $ unless you want the value of the column.

BEGIN{
    FS=";";
    OFS=";";
    print "Average;Missing"
    }
NR>1{
    sum=0;
    c=0;
    for(i=1;i<=NF;i++)
        if($i != "--") {
            sum += $i;
            c++; 
        }
    print sum/c, NF-c;
}

Answer 2

[Kevin Blighe]

Solution already posted, but here is my own:

cat test
a;b;c;d;e;f;g;h
9;8;7;0;--;--;9
5;5;345;3;6;65;8
--;677;888;66;77;--;4
1;2;4;6;8;--;0;6

awk 'BEGIN {FS=";";OFS=";";SUM=0;MSS=0} {
  if (NR==1) {
    print "Sum\tAverage\tMissing"
  } else {
    for (i=1;i<=NF;i++) {
      if ($i!="--") {SUM+=$(i)} else {MSS+=1}
  } print SUM"\t"SUM/(NF-MSS)"\t"MSS; SUM=0; MSS=0}}' test

Sum     Average Missing
33      6.6     2
437     62.4286 0
1712    342.4   2
27      3.85714 1

Answer 3

[Lisa Ha]

Try this:

awk 'BEGIN {FS=OFS=";"};NR==1{print $0,"sum","miss"}; NR>1{sum=miss=0;for (i=1;i<=NF;i++) if($i=="NA"){miss+=1} else if ($i>0){sum+=$i} ; print $0,sum,miss;}' file

Input file:

var1;var2;var3
1;2;3
4;NA;6
7;8;NA

Output:

var1;var2;var3;sum;miss
1;2;3;6;0
4;NA;6;10;1
7;8;NA;15;1