rand:

Syntax:	rand ( )
	rand ( nrow , ncol )

	rand ( "type" )
	rand ( "type" , d1 )
	rand ( "type" , d1 , d2 )

Description:

	rand() creates a random scalar, or matrix.

	`rand()' produces a random scalar.

	`rand ( X , Y )' produces a randomly generated MATRIX with row
	dimension X, and column dimension Y.

	`rand ( "type" , ... )' changes the distribution used when
	generating random numbers. The value of type determines the
	subsequent parameters.

	type:

	rand( "beta" , A , B )

	Sets the generator to return a random deviate from the
	beta distribution  with parameters A and B.  The density of
	the beta is 
               x^(a-1) * (1-x)^(b-1) / B(a,b) for 0 < x < 1

	rand ( "chi" , DF )

	Sets the generator to return a random deviate from the
	distribution of a chi-square with DF degrees of freedom random
	variable.

	rand ( "exp" , AV )

	Sets the generator to return a random deviate from an
	exponential distribution with mean AV.
	
	rand ( "f" , DFN  DFD )

	Sets the generator to return a random deviate from the F
	(variance ratio) distribution with DFN degrees of freedom in
	the numerator and DFD degrees of freedom in the denominator.

	rand ( "gamma" , A , R )

	Sets the generator to return a random deviate from the gamma
	distribution whose density is:

		(A**R)/Gamma(R) * X**(R-1) * Exp(-A*X)

	rand ( "nchi" , DF , XNONC )

	Sets the generator to return a random deviate from the
	distribution of a noncentral chi-square with DF degrees of
	freedom and noncentrality parameter XNONC.

	rand ( "nf" , DFN , DFD, XNONC )

	Sets the generator to return a random deviate from the
	noncentral F (variance ratio) distribution with DFN degrees of
	freedom in the numerator, and DFD degrees of freedom in the
	denominator, and noncentrality parameter XNONC.

	rand ( "normal" , AV , SD )

	Sets the generator to return a random deviate from a normal
	distribution with mean, AV, and standard deviation, SD.

	rand ( "uniform" , LOW , HIGH )

	Sets the generator to return a uniform double between LOW and
	HIGH

	rand ( "bin" , N , P )

	Returns a single random deviate from a binomial distribution
	whose number of trials is N and whose probability of an event
	in each trial is P. 

	rand ( "poisson" , AV )

	Sets the generator to return a random deviate from a
	Poisson distribution with mean AV.

	rand ( "default" )

	Resets the random number generator to the default generator,
	which generates a distributed random variable in the interval
	0 -> 1. The interval endpoints are not returned.

	Examples:

	> rand()
	       0.368
	> rand(4)
	 vector elements 1 thru 4
	       0.983       0.535       0.766       0.646
	> rand(3,3)
	 matrix columns 1 thru 3
	       0.767       0.152       0.347
	        0.78       0.625       0.917
	       0.823       0.315        0.52


	> rand("norm", 10.0, 2.0 );
	> rand(10)
	 vector elements 1 thru 5
	        9.86        11.8        12.1        7.35        8.76
	 vector elements 6 thru 10
	        10.5        7.44        11.1        6.93        9.87


	rand() uses the RANLIB library, authored by B. W. Brown and 
	J. Lovato under grant CA-16672 from the National Cancer
	Institute. 


See Also: srand
