LAPACK 3.12.0
LAPACK: Linear Algebra PACKage

subroutine sgesv  (  integer  n, 
integer  nrhs,  
real, dimension( lda, * )  a,  
integer  lda,  
integer, dimension( * )  ipiv,  
real, dimension( ldb, * )  b,  
integer  ldb,  
integer  info  
) 
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SGESV computes the solution to a real system of linear equations A * X = B, where A is an NbyN matrix and X and B are NbyNRHS matrices. The LU decomposition with partial pivoting and row interchanges is used to factor A as A = P * L * U, where P is a permutation matrix, L is unit lower triangular, and U is upper triangular. The factored form of A is then used to solve the system of equations A * X = B.
[in]  N  N is INTEGER The number of linear equations, i.e., the order of the matrix A. N >= 0. 
[in]  NRHS  NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. 
[in,out]  A  A is REAL array, dimension (LDA,N) On entry, the NbyN coefficient matrix A. On exit, the factors L and U from the factorization A = P*L*U; the unit diagonal elements of L are not stored. 
[in]  LDA  LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). 
[out]  IPIV  IPIV is INTEGER array, dimension (N) The pivot indices that define the permutation matrix P; row i of the matrix was interchanged with row IPIV(i). 
[in,out]  B  B is REAL array, dimension (LDB,NRHS) On entry, the NbyNRHS matrix of right hand side matrix B. On exit, if INFO = 0, the NbyNRHS solution matrix X. 
[in]  LDB  LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). 
[out]  INFO  INFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value > 0: if INFO = i, U(i,i) is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed. 
Definition at line 123 of file sgesv.f.