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DRANDDISCRETEUNIFORM / SRANDDISCRETEUNIFORM

Generates a vector of random variates from a Uniform distribution with probability f(X) defined by: f(X) = 1 / [B - A], X=A,A+1,...,B

(Note that SRANDDISCRETEUNIFORM is the single precision version of DRANDDISCRETEUNIFORM. The argument lists of both routines are identical except that any double precision arguments of DRANDDISCRETEUNIFORM are replaced in SRANDDISCRETEUNIFORM by single precision arguments - type REAL in FORTRAN or type float in C).

— SUBROUTINE: DRANDDISCRETEUNIFORM (N,A,B,STATE,X,INFO)
— Input: INTEGER N

On input: number of variates required.
Constraint: N>=0.

— Input: INTEGER A

On input: minimum for the distribution.

— Input: INTEGER B

On input: maximum for the distribution.
Constraint: B>=A.

— Input/Output: INTEGER STATE(*)

The STATE vector holds information on the state of the base generator being used and as such its minimum length varies. Prior to calling DRANDDISCRETEUNIFORM STATE must have been initialized. See Initialization of the Base Generators for information on initialization of the STATE variable.
On input: the current state of the base generator.
On output: the updated state of the base generator.

— Output: INTEGER X(N)

On output: vector of variates from the specified distribution.

— Output: INTEGER INFO

On output: INFO is an error indicator. On successful exit, INFO contains 0. If INFO = -i on exit, the i-th argument had an illegal value. 

     Example:
     

     
          C      Generate 100 values from the Uniform distribution
                 INTEGER LSTATE,N
                 PARAMETER (LSTATE=16,N=100)
                 INTEGER I,INFO,SEED(1),STATE(LSTATE)
                 INTEGER A,B
                 INTEGER X(N)
          C      Set the seed
                 SEED(1) = 1234
          
          C      Read in the distributional parameters
                 READ(5,*) A,B
          
          C      Initialize the STATE vector
                 CALL DRANDINITIALIZE(1,1,SEED,1,STATE,LSTATE,INFO)
          C      Generate N variates from the Uniform distribution
                 CALL DRANDDISCRETEUNIFORM(N,A,B,STATE,X,INFO)
          
          C      Print the results
                 WRITE(6,*) (X(I),I=1,N)