IStatistics.TInv

Syntax

TInv(Probability: Double; DegreesOfFreedom: Integer): Double;

Parameters

Probability. Probability corresponding to two-tailed distribution. Tolerance range: [0, 1].

DegreesOfFreedom. The number of degrees of freedom describing the distribution. Value must satisfy the following constraint: DegreesOfFreedom >= 1.

Description

The TInv method returns the t-value of the Student's distribution as the function of probability and the number of degrees of freedom.

Comments

You can calculate the single-sided t-value be replacing the Probability argument with 2*Probability.

Example

To execute the example, add a link to the Stat system assembly.

Sub UserProc;
Var
    st: Statistics;
    d0: Double;
Begin
    st := New Statistics.Create;
    d0 := st.TInv(0.004,56);
    If st.Status <> 0 Then
        Debug.WriteLine(st.Errors);
    Else
        Debug.WriteLine("t value: " + d0.ToString);
    End If;
End Sub UserProc;

After you have executed this example the console window shows the t-value of the Student's distribution:

Unit execution started

t value: 3.00216157211437

Unit execution finished