---
name: "dznrm2.f90"
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/dznrm2.f90"
---

# dznrm2.f90(3)

## NAME

BLAS/SRC/dznrm2.f90

## SYNOPSIS

### Functions/Subroutines

real(wp) function **dznrm2** (n, x, incx)\
 **DZNRM2**

## Function/Subroutine Documentation

### real(wp) function dznrm2 (integer n, complex(wp), dimension(\*) x, integer incx)

**DZNRM2**

**Purpose:**

```
!>
!> DZNRM2 returns the euclidean norm of a vector via the function
!> name, so that
!>
!>    DZNRM2 := sqrt( x**H*x )
!>
```

**Parameters**

*N*

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

*X*

```
!>          X is COMPLEX*16 array, dimension (N)
!>         complex vector with N elements
!>
```

*INCX*

```
!>          INCX is INTEGER, storage spacing between elements of X
!>          If INCX > 0, X(1+(i-1)*INCX) = x(i) for 1 <= i <= n
!>          If INCX < 0, X(1-(n-i)*INCX) = x(i) for 1 <= i <= n
!>          If INCX = 0, x isn't a vector so there is no need to call
!>          this subroutine.  If you call it anyway, it will count x(1)
!>          in the vector norm N times.
!>
```

**Author**

Edward Anderson, Lockheed Martin

**Date**

August 2016

**Contributors:**

Weslley Pereira, University of Colorado Denver, USA

**Further Details:**

```
!>
!>  Anderson E. (2017)
!>  Algorithm 978: Safe Scaling in the Level 1 BLAS
!>  ACM Trans Math Softw 44:1--28
!>  https://doi.org/10.1145/3061665
!>
!>  Blue, James L. (1978)
!>  A Portable Fortran Program to Find the Euclidean Norm of a Vector
!>  ACM Trans Math Softw 4:15--23
!>  https://doi.org/10.1145/355769.355771
!>
!>
```

Definition at line **89** of file **dznrm2.f90**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.