hi all, i have the following problem using awk in a script

i want to read the values from a column with real numbers and calculate the mean.the problem is that when i use a statement such as this

num = $4

i cant find a way to convert the variable from string to floating point to perform any operations.i tried the following

sum = num + 0.0

but sum is equal to 0 after this statement, num is not treated as floating point number but as string

any help would be appreciated

edit : i am using awk 3.1.4 on Suse 9.2

what "operation" are you trying to perform?
for example:
echo '1.2' | nawk '{num=$1; print num, num+3.5}'

i just want to do simple mathematical operations.to be more clear here is a test awk script i used

BEGIN{}

{

num = $1
sum += num

}

END {
print sum
}

where column 1 contains the floating point numbers
print sum produces 0...

i tried to add 0.0 to num to force to be treated as number and not as string but that didnt work either

produces a fine floating point number for me - Solaris's nawk:

nawk '{sum +=$1} END{print sum}' <<!
1.2
1.3
1.4
!

neither awk or gawk works for me...
anyway thanks for replying

works under gawk for me....
there must be something strange with your 'data source'