?laran

Returns a random real number from a uniform distribution.

Syntax

float slaran (lapack_int *iseed);

double dlaran (lapack_int *iseed);

Description

The ?laran routine returns a random real number from a uniform (0,1) distribution. This routine uses a multiplicative congruential method with modulus 2⁴⁸ and multiplier 33952834046453. 48-bit integers are stored in four integer array elements with 12 bits per element. Hence the routine is portable across machines with integers of 32 bits or more.

Input Parameters

iseed: Array, size 4. On entry, the seed of the random number generator. The array elements must be between 0 and 4095, and iseed[3] must be odd.

Output Parameters

iseed

On exit, the seed is updated.

Return Values

The function returns a random number.