CODEWITHSUNDEEP
awkcalculated-columnssubtraction
Vonton
Vonton

Reputation: 3344

Awk Subtract value from columns

I need help with this in AWK. I would like to subtract value of the second column from the first row from the first row from second column (20 - 15, 40 - 35, 45 - 45, etc.)

INPUT FILE

 10   15 
 20   35 
 40   45 
 45   55 
 58   70

OUTPUT FILE

5
5
0
3

Thank you.

Upvotes: 1

Views: 5271

Answers (2)

suhas
suhas

Reputation: 733

cat numb

10   15
20   35
40   45
45   55
58   70

so to perform action

awk 'p{print $1-p}{p=$2}' numb

output

5
5
0
3

Upvotes: 3

fedorqui
fedorqui

Reputation: 289525

You can do this:

$ awk 'NR==1 {a=$2; next} {print $1 - a; a=$2}' file
5
5
0
3

Explanation

It keeps track of the 2nd value and stores in the variable a.

  • NR==1 {a=$2; next} if we are in the first record (line), just store the 2nd col.
  • {print $1 - a; a=$2} from that moment, print the difference between 1st column and stored value. Then, store the 2nd col of current line, to be used in the following line.

Upvotes: 1

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