Description of gesv

gesv		Programmers Guide
		Contents \| Index \| Search

Category:mtl2lapack

Component type:function

Prototype

template <class LapackMatA, class LapackMatB, class VectorInt> int gesv(LapackMatA& a, VectorInt & ipivot, LapackMatB& b) ;

Description

Computes the solution to a real system of linear equations A*X=B (simple driver). LU decomposition with partial pivoting and row interchanges is used to solve the system.

a (IN/OUT - matrix(M,N)) On entry, the coefficient matrix A, and the factors L and U from the factorization A = P*L*U on exit.
ipivot (OUT - vector(N)) Integer vector. The row i of A was interchanged with row IPIV(i).
b (IN/OUT - matrix(ldb,NRHS)) Matrix of same numerical type as A. On entry, the NxNRHS matrix of the right hand side matrix B. On a successful exit, it is the NxNRHS solution matrix X.
info (OUT - int) 0 : function completed normally < 0 : The ith argument, where i = abs(return value) had an illegal value. > 0 : U(i,i), where i = return value, is exactly zero and U is therefore singular. The LU factorization has been completed, but the solution could not be computed.

Definition

mtl2lapack.h

Preconditions

Complexity

Example

Notes

See also