Determinant of a Triangular Matrix

DESCRIPTION:

Computes the determinant (or its logarithm) of a triangular Matrix. .LB Matrix

USAGE:

det.LowerTriangular(x, logarithm=T) 
det.UpperTriangular(x, logarithm=T) 
det.UnitLowerTriangular(x, logarithm=T) 
det.UnitUpperTriangular(x, logarithm=T) 

REQUIRED ARGUMENTS:

x
a triangular Matrix, that is, a Matrix inheriting from class "Matrix" , and from one of "LowerTriangular" , "UpperTriangular" , "UnitLowerTriangular" , and "UnitUpperTriangular" .

OPTIONAL ARGUMENTS:

logarithm
a logical variable indicating whether or not the logarithm of the modulus of the determinant should be returned rather than the determinant itself. The default is to return the logarithm.

VALUE:

returns an object of class "det" .

REFERENCES:

Golub, G., and Van Loan, C. F. (1989). Matrix Computations, 2nd edition, Johns Hopkins, Baltimore.

SEE ALSO:

, .

EXAMPLES:

x <- Matrix( sample(-3:3, size = 9, replace = T), nrow = 3, ncol = 3) 
x[row(x) > col(x)] <- 0        # construct triangular matrix 
class(x) <-  Matrix.class(x) 
det(x)