For Origin C:

double Landaupdf( const double x, double mu = 0, double sigma = pi/2 )

double Landaucdf( const double x, double mu = 0, double sigma = pi/2, int iTail = TAILED_TEST_LOWER )

double Landauinv( const double dP, double mu=0, double sigma=pi/2 )

For LabTalk:

double Landaupdf( double x, double mu, double sigma )

double Landaucdf( double x, double mu, double sigma[, int Tail] )

double Landauinv( double p, double mu, double sigma )