IStatistics.Poisson

Syntax

Poisson(EventCount: Integer; Mean: Double; Cumulative: Boolean): Double;

Parameters

EventCount. The number of events. This value must meet the following constraint: EventCount > 0.

Mean. Expected numeric value.

Cumulative. Boolean values that defines form of returned probability distribution:

True. This method returns integral Poisson distribution, that is the probability for a number of random events to be between 0 and EventCount inclusive.
False. The method returns the Poisson distribution density function, i.e. the probability for the number of events to be exactly as much as EventCount.

Description

The Poisson method returns the Poisson distribution.

Comments

Poisson distribution is used to predict the number of events occurring in a fixed interval of time.

Example

Sub UserProc;
Var
    st: Statistics;
    d0: Double;
Begin
    st := New Statistics.Create;
    d0 := st.Poisson(2, 5, False);
    If st.Status <> 0 Then
        Debug.WriteLine(st.Errors);
    Else
        Debug.WriteLine("Function of Poisson distribution density: " + d0.ToString);
    End If;
End Sub UserProc;

After you have executed this example the console window shows the value of the Poisson distribution density function.

Module execution started

Poisson's distribution density function: 0.084224337488568349

Module execution finished