awk sum giving incorrect value

Shell Programming and Scripting
1 
 
cat T|awk -v format=$format '{ SUM += $1} END { printf format,SUM}'

the file T has below data

 
usghrt45tf:hrguat:/home/hrguat $ cat T
-1363000.00123456789
-95000.00789456123
-986000.0045612378
-594000.0015978
-368939.54159753258415
-310259.0578945612
-133197.37123456789
-12475383.16789456123
-2812276.0312345678

the output of above command is "-19138055.18514395505190" with format set to

format='%22.14f'

the actual result of the sum should be "-19138055.18514395762415"
It looks like the unix is approximating the last 6 digits in the scale. Could any one please help ?

2

Try:

sum=0;while read n; do sum=`echo "scale=14;$sum+$n"| bc`; done < T; echo $sum
3 
sum=0;while read n; do sum=`echo "scale=14;$sum+$n"| bc`; done < T; echo $sum

this works but the only point which holds me back is, the above should iterate for each record and might be time consuming when there huge number of records.

4

Try:

awk '{$1=$1}1' OFS=+ RS=X infile | bc

or to specify a precise precision:

awk 'BEGIN{print "scale=14; "} {$1=$1}1' OFS=+ RS= infile
5

The result is same as cat on the file name, guess something is missing