logon index / find a computer's main user

logonindex.ps1

$ComputerName = $env:ComputerName

$test = Import-Csv -Path "log:\computers\${ComputerName}.log" -Delimiter ' ' -header @('user','date','time')

$t2 = $test |
select user,date,@{
    name='logonage';
    expression={
        1 / ((Get-Date) - [DateTime]$_.date).Days}
} |
group user |
select Count,Name,@{
    Name='index';
    Expression={
        "{0:N2}" -f (($_.Group | measure -Property logonage -Average).Average * $_.count * 10)
    }
}

$t2