IStatistics.NormDist

Syntax

NormDist(Value: Double; Mean: Double; StandartDeviation: Double; Cumulative: Boolean): Double;

Parameters

Value. The value for which the distribution is set.

Mean. Arithmetic mean of the distribution.

StandartDeviation. Standard deviation of the distribution. Value must satisfy the following constraint: StandartDeviation > 0.

Cumulative. Boolean value that defines function form:

When the value is True the NormDist function returns cumulative distribution function.
If the value is False, the function returns the distribution density function.

Description

The NormDist method returns the normal distribution function for the specified mean and standard deviation.

Comments

This function is widely used in statistics, including hypothesis testing.

Example

Sub UserProc;
Var
    st: Statistics;
    d0, d1: Double;
Begin
    st := New Statistics.Create;
    d0 := st.NormDist(12, 3, 2.5, True);
    d1 := st.NormDist(12, 3, 2.5, False);
    If st.Status <> 0 Then
        Debug.WriteLine(st.Errors);
    Else
        Debug.WriteLine(" Distribution integral function: " + d0.ToString);
        Debug.WriteLine(" Distribution density function: " + d0.ToString);
    End If;
End Sub UserProc;

Executing this example shows the calculation results in the console window.

Module execution started

Distribution integral function: 0.99984089140984245

Distribution density function: 0.00024476077204550875

Module execution finished