line by line subraction

[rhnaeco]

I'm not sure whether this is a sed or awk solution:

i have a file like this :

12.4277 -12.9941
12.4277 -13.2078
12.4278 -13.3616
12.4278 -13.3616
.... .... ....

i would like to subract the values in $3 from each other, e.g.
-13.2078 - -12.9941 = column in new file
-13.3616 - -13.2078 = same column

so that my results look like:
-0.2137
-0.1538
0

this column i would like to sum
e.g -0.3675

any help would be greatly apprieciated

thanks
rhnaeco

 

[PHV]

A starting point:
awk 'NR>1{d=$2-s;t+=d;print d}{s=$2}END{print t}' /path/to/input > output

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[rhnaeco]

thank you, but is it possible to create the file of 'sums' as well, as there are other commands i need to carry out on these for a separate result.

sorry, i wasn't particularly clear

thanks
Rhnaeco