cgesv.f man page

cgesv.f —

Synopsis

Functions/Subroutines

subroutine cgesv (N, NRHS, A, LDA, IPIV, B, LDB, INFO)
CGESV computes the solution to system of linear equations A * X = B for GE matrices (simple driver)

Function/Subroutine Documentation

subroutine cgesv (integerN, integerNRHS, complex, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, complex, dimension( ldb, * )B, integerLDB, integerINFO)

CGESV computes the solution to system of linear equations A * X = B for GE matrices (simple driver)

Purpose:

CGESV computes the solution to a complex system of linear equations
   A * X = B,
where A is an N-by-N matrix and X and B are N-by-NRHS 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.

Parameters:

N

N is INTEGER
The number of linear equations, i.e., the order of the
matrix A.  N >= 0.

NRHS

NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B.  NRHS >= 0.

A

A is COMPLEX array, dimension (LDA,N)
On entry, the N-by-N 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.

LDA

LDA is INTEGER
The leading dimension of the array A.  LDA >= max(1,N).

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).

B

B is COMPLEX array, dimension (LDB,NRHS)
On entry, the N-by-NRHS matrix of right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS solution matrix X.

LDB

LDB is INTEGER
The leading dimension of the array B.  LDB >= max(1,N).

INFO

INFO is INTEGER
= 0:  successful exit
< 0:  if INFO = -i, the i-th 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.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Definition at line 123 of file cgesv.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

cgesv(3) is an alias of cgesv.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK