---
name: "zgeru.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/zgeru.f"
---

# zgeru.f(3)

## NAME

BLAS/SRC/zgeru.f

## SYNOPSIS

### Functions/Subroutines

subroutine **zgeru** (m, n, alpha, x, incx, y, incy, a, lda)\
 **ZGERU**

## Function/Subroutine Documentation

### subroutine zgeru (integer m, integer n, complex\*16 alpha, complex\*16, dimension(\*) x, integer incx, complex\*16, dimension(\*) y, integer incy, complex\*16, dimension(lda,\*) a, integer lda)

**ZGERU**

**Purpose:**

```
!>
!> ZGERU  performs the rank 1 operation
!>
!>    A := alpha*x*y**T + A,
!>
!> where alpha is a scalar, x is an m element vector, y is an n element
!> vector and A is an m by n matrix.
!>
```

**Parameters**

*M*

```
!>          M is INTEGER
!>           On entry, M specifies the number of rows of the matrix A.
!>           M must be at least zero.
!>
```

*N*

```
!>          N is INTEGER
!>           On entry, N specifies the number of columns of the matrix A.
!>           N must be at least zero.
!>
```

*ALPHA*

```
!>          ALPHA is COMPLEX*16
!>           On entry, ALPHA specifies the scalar alpha.
!>
```

*X*

```
!>          X is COMPLEX*16 array, dimension at least
!>           ( 1 + ( m - 1 )*abs( INCX ) ).
!>           Before entry, the incremented array X must contain the m
!>           element vector x.
!>
```

*INCX*

```
!>          INCX is INTEGER
!>           On entry, INCX specifies the increment for the elements of
!>           X. INCX must not be zero.
!>
```

*Y*

```
!>          Y is COMPLEX*16 array, dimension at least
!>           ( 1 + ( n - 1 )*abs( INCY ) ).
!>           Before entry, the incremented array Y must contain the n
!>           element vector y.
!>
```

*INCY*

```
!>          INCY is INTEGER
!>           On entry, INCY specifies the increment for the elements of
!>           Y. INCY must not be zero.
!>
```

*A*

```
!>          A is COMPLEX*16 array, dimension ( LDA, N )
!>           Before entry, the leading m by n part of the array A must
!>           contain the matrix of coefficients. On exit, A is
!>           overwritten by the updated matrix.
!>
```

*LDA*

```
!>          LDA is INTEGER
!>           On entry, LDA specifies the first dimension of A as declared
!>           in the calling (sub) program. LDA must be at least
!>           max( 1, m ).
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Further Details:**

```
!>
!>  Level 2 Blas routine.
!>
!>  -- Written on 22-October-1986.
!>     Jack Dongarra, Argonne National Lab.
!>     Jeremy Du Croz, Nag Central Office.
!>     Sven Hammarling, Nag Central Office.
!>     Richard Hanson, Sandia National Labs.
!>
```

Definition at line **129** of file **zgeru.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.