### PDA_RAND

Returns pseudo-random numbers in the range 0 to 1

#### Description:

This is a simple random number generator providing deviates in the range 0 to 1, with period of 2$\ast$$\ast$26, and to 6 or 7 digits accuracy. It is based upon Ahrens, Dieter & Grube’s TOMS599 routines. Note that there is no STATUS argument for efficiency.

#### Invocation

RESULT = PDA_RAND( X )

#### Arguments

##### X = REAL (Given)
This is a dummy variable required by the Fortran standard.

#### Returned Value

##### PDA_RAND = REAL
The pseudo-random deviate.

#### Prior Requirements

The initial seed MUST be set using routine PDA_RNSED (equivalent to NAG’s G05CBF). If it has not, there is no guarantee that sensible values will be returned from this function.

#### References

Ahrens, J.H., Dieter, U. & Grube, A., 1970, "Pseudo-random numbers: a new proposal for the choice of multiplicators", Computing, 6, pp.121–138.