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Text File | 1994-04-25 | 2.9 KB | 120 lines | [TEXT/EDIT] |
- 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 )
-
- Returns a single 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 )
-
- Generates random deviate from the distribution of a chi-square
- with DF degrees of freedom random variable.
-
- rand ( "exp" , AV )
-
- Generates a single random deviate from an exponential
- distribution with mean AV.
-
- rand ( "f" , DFN DFD )
-
- Generates 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 )
-
- Generates random deviates from the gamma distribution whose
- density is
- (A**R)/Gamma(R) * X**(R-1) * Exp(-A*X)
-
- rand ( "nchi" , DF , XNONC )
-
- Generates random deviate from the distribution of a noncentral
- chi-square with DF degrees of freedom and noncentrality
- parameter XNONC.
-
- rand ( "nf" , DFN , DFD, XNONC )
-
- Generates 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 )
-
- Generates a single random deviate from a normal distribution
- with mean, AV, and standard deviation, SD.
-
- rand ( "uniform" , LOW , HIGH )
-
- Generate 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 )
-
- Generates a single 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
-