---
name: "dlaran.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/dlaran.f"
---

# dlaran.f(3)

## NAME

TESTING/MATGEN/dlaran.f

## SYNOPSIS

### Functions/Subroutines

double precision function **dlaran** (iseed)\
 **DLARAN**

## Function/Subroutine Documentation

### double precision function dlaran (integer, dimension( 4 ) iseed)

**DLARAN**

**Purpose:**

```
!>
!> DLARAN returns a random real number from a uniform (0,1)
!> distribution.
!>
```

**Parameters**

*ISEED*

```
!>          ISEED is INTEGER array, dimension (4)
!>          On entry, the seed of the random number generator; the array
!>          elements must be between 0 and 4095, and ISEED(4) must be
!>          odd.
!>          On exit, the seed is updated.
!>
```

**Author**

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

**Further Details:**

```
!>
!>  This routine uses a multiplicative congruential method with modulus
!>  2**48 and multiplier 33952834046453 (see G.S.Fishman,
!>  'Multiplicative congruential random number generators with modulus
!>  2**b: an exhaustive analysis for b = 32 and a partial analysis for
!>  b = 48', Math. Comp. 189, pp 331-344, 1990).
!>
!>  48-bit integers are stored in 4 integer array elements with 12 bits
!>  per element. Hence the routine is portable across machines with
!>  integers of 32 bits or more.
!>
```

Definition at line **66** of file **dlaran.f**.

## Author

Generated automatically by Doxygen for LAPACK from the source code.