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Student's t probability density function (pdf).
Syntax
Y = tpdf(X,V)
Description
tpdf(X,V) computes Student's t pdf with parameter V at the values in X. The arguments X and V must be the same size except that a scalar argument functions as a constant matrix of the same size of the other argument. The degrees of freedom, V, must be a positive integer. Student's t pdf is:
Examples
The mode of the t distribution is at x = 0. This example shows that the value of the function at the mode is an increasing function of the degrees of freedom.tpdf(0,1:6)
ans =
0.3183 0.3536 0.3676 0.3750 0.3796 0.3827
The t distribution converges to the standard normal distribution as the degrees of freedom approaches infinity. How good is the approximation for v = 30?
difference = tpdf(-2.5:2.5,30) - normpdf(-2.5:2.5)
difference =
0.0035 -0.0006 -0.0042 -0.0042 -0.0006 0.0035