can i view 95 percentile line in a report graph

The following PowerShell demonstrates how to generate a sensor factory definition to retrieve a one time snapshot of a specified percentile using PrtgAPI, based on the algorithm described in Paessler's support article

# Specify the percentile to calculate, e.g. 95
function CalculatePercentile($sensors, $val)
{
    # 1. Sort the measurements
    $sorted = $sensors|sort lastvalue

    # 2. Calculate RN
    $n = $sorted.Count
    $p = $val / 100
    $rn = 1 + ($n - 1) * $p

    Write-Verbose "RN is $rn"

    # 3. Calculate result
    $floorRN = [Math]::Floor($rn)
    $ceilingRN = [Math]::Ceiling($rn)

    Write-Verbose "FloorRN is $floorRN, CeilingRN is $ceilingRN"

    $result = $null

    if($rn -eq $floorRN -eq $ceilingRN)
    {
        $result = $rn
    }
    else
    {
        $floorRNVal = $sensors[$floorRN - 1].LastValue
        $ceilingRNVal = $sensors[$ceilingRN - 1].LastValue

        Write-Verbose "FloorRNVal is $floorRNVal, CeilingRNVal is $ceilingRNVal"

        $result = $floorRNVal + ($rn - $floorRN) * ($ceilingRNVal - $floorRNVal)
    }

    Write-Verbose "$($val)th Percentile is $result"

    return $result
}

function TestMath
{
    $VerbosePreference = "Continue"
    $sensors = Get-Sensor ping -count 8|sort lastvalue
    $sensors[0].LastValue = 1
    $sensors[1].LastValue = 3
    $sensors[2].LastValue = 7
    $sensors[3].LastValue = 21
    $sensors[4].LastValue = 25
    $sensors[5].LastValue = 26
    $sensors[6].LastValue = 66
    $sensors[7].LastValue = 72
    $percentile = CalculatePercentile $sensors 95
}

$sensors = Get-Sensor ping -count 30|sort lastvalue
$percentile = CalculatePercentile $sensors 95

$sensors | New-SensorFactoryDefinition { $_.Device } -ChannelId 0
$sensors | New-SensorFactoryDefinition -Name { "Line at $percentile [msec]" } -Aggregator { $percentile } 0 -StartId ($sensors.Count + 1)

By default, the script will output the channel definitions required to create a sensor factory using the first 30 Ping sensors retrieved from your PRTG as well as a horizontal line at the 95th percentile of the Ping Time channel

To apply this to a different channel or sensor type, simply modify the call to Get-Sensor, adjust the -ChannelId specified to New-SensorFactoryDefinition and modify the channel unit used for displaying the horizontal line.

To verify the implementation of Paessler's percentile calculation formula, you can optionally run the TestMath function. This will retrieve 8 sensors from your server and then plug in the values that were used in Paessler's calculation example, emitting the various variables used in calculating the formula

Regards,

lordmilko