g05 Chapter Contents
g05 Chapter Introduction
NAG C Library Manual

# NAG Library Function Documentnag_rand_basic (g05sac)

## 1  Purpose

nag_rand_basic (g05sac) generates a vector of pseudorandom numbers taken from a uniform distribution between $0$ and $1$.

## 2  Specification

 #include #include
 void nag_rand_basic (Integer n, Integer state[], double x[], NagError *fail)

## 3  Description

nag_rand_basic (g05sac) generates $n$ values from a uniform distribution over the half closed interval $\left(0,1\right]$.
One of the initialization functions nag_rand_init_repeatable (g05kfc) (for a repeatable sequence if computed sequentially) or nag_rand_init_nonrepeatable (g05kgc) (for a non-repeatable sequence) must be called prior to the first call to nag_rand_basic (g05sac).

## 4  References

Knuth D E (1981) The Art of Computer Programming (Volume 2) (2nd Edition) Addison–Wesley

## 5  Arguments

1:     nIntegerInput
On entry: $n$, the number of pseudorandom numbers to be generated.
Constraint: ${\mathbf{n}}\ge 0$.
2:     state[$\mathit{dim}$]IntegerCommunication Array
Note: the actual argument supplied must be the array state supplied to the initialization functions nag_rand_init_repeatable (g05kfc) or nag_rand_init_nonrepeatable (g05kgc).
On entry: contains information on the selected base generator and its current state.
On exit: contains updated information on the state of the generator.
3:     x[n]doubleOutput
On exit: the $n$ pseudorandom numbers from a uniform distribution over the half closed interval $\left(0,1\right]$.
4:     failNagError *Input/Output
The NAG error argument (see Section 3.6 in the Essential Introduction).

## 6  Error Indicators and Warnings

On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_INT
On entry, ${\mathbf{n}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{n}}\ge 0$.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
NE_INVALID_STATE
On entry, state vector has been corrupted or not initialized.

Not applicable.

Not applicable.

## 9  Example

This example prints the first five pseudorandom numbers from a uniform distribution between $0$ and $1$, generated by nag_rand_basic (g05sac) after initialization by nag_rand_init_repeatable (g05kfc).

### 9.1  Program Text

Program Text (g05sace.c)

None.

### 9.3  Program Results

Program Results (g05sace.r)