Introduction - If you have any usage issues, please Google them yourself
LU decomposition is essentially a Gaussian elimination method expression. A substance is through the primary transformation into an upper triangular matrix, the transformation matrix is a unit lower triangular matrix. This is the so-called Duerlite algorithms (Doolittle algorithm): from the bottom row of the matrix A do elementary transformation, the diagonal elements into the bottom left of zero, and then show the effect of these lines is equivalent to transform the left by a unit lower triangular matrix, this series of unit lower triangular matrix inverse is the product of L matrices, it is also a unit lower triangular matrix. The complexity of these algorithms is generally about the full elimination of the decomposition is not.