CODEWITHSUNDEEP
linuxshellawk
Kay
Kay

Reputation: 2077

Print a selective column after subtraction from another file

I have two files with equal number of rows and columns. I would like to subtract the 2nd column in one file from the 2nd column in another file without considering the missing values. e.g.

ifile1.txt    
3  5  2  2
1  ?  2  1
4  6  5  2
5  5  7  1

ifile2.txt
1  2  1  3
1  3  0  2
2  ?  5  1
0  0  1  1

Here "?" is the missing value and should not be considered in computation.

ofile.txt i.e. [$2(ifile1.txt) - $2(ifile2.txt)]
3
?
?
5

I could able to do it without any missing values in following way. But can't able to succeed with a missing value like here "?".

paste ifile1.txt ifile2.txt > ifile3.txt
awk '{n=NF/2; for (i=1;i<=n;i++) printf "%5.2f ", $i-$(i+n); print ""}' ifile3.txt > ifile4.txt
awk '{printf ("%.2f\n",$2)}' ifile4.txt > ofile.txt

Upvotes: 0

Views: 56

Answers (2)

agc
agc

Reputation: 8406

POSIX shell script, and paste.

paste ifile[12].txt | \
 while read a b c d  e f g ; do \
       [ "$b$f" -eq "$b$f" ] 2> /dev/null \
         && echo $(( b - f )) \
         || echo '?' ; \
 done

Output:

3
?
?
5

Upvotes: 1

Ed Morton
Ed Morton

Reputation: 203532

$ awk 'NR==FNR{a[NR]=$2;next} {print ((a[FNR]$2)~/?/ ? "?" : a[FNR]-$2)}' file1 file2
3
?
?
5

Upvotes: 3

Related Questions