---
name: "sgesv.f"
section: "3"
platform: "linux"
package: "lapack-doc"
version: "3.12.1-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/sgesv.f"
---

# sgesv.f(3)

## NAME

SRC/sgesv.f

## SYNOPSIS

### Functions/Subroutines

subroutine **sgesv** (n, nrhs, a, lda, ipiv, b, ldb, info)\

## Function/Subroutine Documentation

### subroutine sgesv (integer n, integer nrhs, real, dimension( lda, \* ) a, integer lda, integer, dimension( \* ) ipiv, real, dimension( ldb, \* ) b, integer ldb, integer info)

**Purpose:**

```
!>
!> SGESV computes the solution to a real 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 REAL 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 REAL 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.

Definition at line **123** of file **sgesv.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.