---
name: "daxpy.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/daxpy.f"
---

# daxpy.f(3)

## NAME

BLAS/SRC/daxpy.f

## SYNOPSIS

### Functions/Subroutines

subroutine **daxpy** (n, da, dx, incx, dy, incy)\
 **DAXPY**

## Function/Subroutine Documentation

### subroutine daxpy (integer n, double precision da, double precision, dimension(\*) dx, integer incx, double precision, dimension(\*) dy, integer incy)

**DAXPY**

**Purpose:**

```
!>
!>    DAXPY constant times a vector plus a vector.
!>    uses unrolled loops for increments equal to one.
!>
```

**Parameters**

*N*

```
!>          N is INTEGER
!>         number of elements in input vector(s)
!>
```

*DA*

```
!>          DA is DOUBLE PRECISION
!>           On entry, DA specifies the scalar alpha.
!>
```

*DX*

```
!>          DX is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
!>
```

*INCX*

```
!>          INCX is INTEGER
!>         storage spacing between elements of DX
!>
```

*DY*

```
!>          DY is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
!>
```

*INCY*

```
!>          INCY is INTEGER
!>         storage spacing between elements of DY
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Further Details:**

```
!>
!>     jack dongarra, linpack, 3/11/78.
!>     modified 12/3/93, array(1) declarations changed to array(*)
!>
```

Definition at line **88** of file **daxpy.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.