---
name: "sum1"
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/sum1"
---

# sum1(3)

sum1: sum \| x\_i \| (in LAPACK)

## NAME

sum1 - sum1: sum \| x\_i \| (in LAPACK)

## SYNOPSIS

### Functions

double precision function **dzsum1** (n, cx, incx)\
 **DZSUM1** forms the 1-norm of the complex vector using the true absolute value.  real function **scsum1** (n, cx, incx)\
 **SCSUM1** forms the 1-norm of the complex vector using the true absolute value.

## Detailed Description

## Function Documentation

### double precision function dzsum1 (integer n, complex\*16, dimension( \* ) cx, integer incx)

**DZSUM1** forms the 1-norm of the complex vector using the true absolute value.

**Purpose:**

```
!>
!> DZSUM1 takes the sum of the absolute values of a complex
!> vector and returns a double precision result.
!>
!> Based on DZASUM from the Level 1 BLAS.
!> The change is to use the 'genuine' absolute value.
!>
```

**Parameters**

*N*

```
!>          N is INTEGER
!>          The number of elements in the vector CX.
!>
```

*CX*

```
!>          CX is COMPLEX*16 array, dimension (N)
!>          The vector whose elements will be summed.
!>
```

*INCX*

```
!>          INCX is INTEGER
!>          The spacing between successive values of CX.  INCX > 0.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Contributors:**

Nick Higham for use with ZLACON.

Definition at line **80** of file **dzsum1.f**.

### real function scsum1 (integer n, complex, dimension( \* ) cx, integer incx)

**SCSUM1** forms the 1-norm of the complex vector using the true absolute value.

**Purpose:**

```
!>
!> SCSUM1 takes the sum of the absolute values of a complex
!> vector and returns a single precision result.
!>
!> Based on SCASUM from the Level 1 BLAS.
!> The change is to use the 'genuine' absolute value.
!>
```

**Parameters**

*N*

```
!>          N is INTEGER
!>          The number of elements in the vector CX.
!>
```

*CX*

```
!>          CX is COMPLEX array, dimension (N)
!>          The vector whose elements will be summed.
!>
```

*INCX*

```
!>          INCX is INTEGER
!>          The spacing between successive values of CX.  INCX > 0.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Contributors:**

Nick Higham for use with CLACON.

Definition at line **80** of file **scsum1.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.