Powershell adding numbers in a loop - powershell

Question

I have the below code which is meant to total up the time offset as the loop rotates (I will then need to divide this by 10 to get the average but first I need to get this bit working).
I'm assuming I need to cast something as [INT] but I've tried multiple locations that would make sense to no avail. I just end up with O's.
$winTimeStripchart = w32tm /stripchart /computer:0.pool.ntp.org /dataonly /samples:10
$WinTimeOffset = $null
For($i=3; $i -le 12; $i++){
$Offset = $winTimeStripchart[$i].split("-")
$trimmedOffset = $Offset[1].trim("s")
$winTimeOffset = $winTimeOffset + $trimmedOffset
}
Write-Host "Total: $winTimeOffset"
# Now need to divide by 10.
sample data:
20:30:23, -00.0698082s
20:30:25, -00.0704645s
20:30:27, -00.0708694s
20:30:29, -00.0728990s
20:30:31, -00.0719226s
20:30:33, -00.0749031s
20:30:36, -00.0778656s
20:30:38, -00.0782183s
20:30:40, -00.0752974s
20:30:42, -00.0760958s

Answer 1

You can try this one line command :
$a = w32tm /stripchart /computer:0.fr.pool.ntp.org /dataonly /samples:10 | select -Skip 3 | % {[double]$_.Substring(11,10)} | Measure-Object -Average -sum
$a can also give you maximum and minimum adding Measure-Object params.

Answer 2

You'll want to cast to a double rather than int. The following should do it:
[System.Collections.ArrayList]$winTimeStripchart = w32tm /stripchart /computer:0.pool.ntp.org /dataonly /samples:10
$WinTimeOffset = $null
$winTimeStripchart.RemoveRange(0,3)
foreach($entry in $winTimeStripchart){
$Offset = $entry.split("-")
$trimmedOffset = $Offset[1].trim("s")
$winTimeOffset = [double]$winTimeOffset + [double]$trimmedOffset
}
Write-Host "Total: $winTimeOffset"
Write-Host "Average: $($winTimeOffset/$winTimeStripchart.count)"
Sample output:
Total: 6.1581437
Average: 0.61581437
I've make some other tweaks to the script as well to make it more scalable:
Foreach rather than a for loop
Using a list rather than array and stripping first 3 entries.
Dividing buy number of entries in list.
regards
Arcas