g05tec generates
integers
from a discrete hypergeometric distribution, where the probability of
is
The variates can be generated with or without using a search table and index. If a search table is used then it is stored with the index in a reference vector and subsequent calls to g05tec with the same parameter values can then use this reference vector to generate further variates. The reference array is generated by a recurrence relation if , otherwise Stirling's approximation is used.
One of the initialization functions
g05kfc (for a repeatable sequence if computed sequentially) or
g05kgc (for a non-repeatable sequence) must be called prior to the first call to
g05tec.
-
1:
– Nag_ModeRNG
Input
-
On entry: a code for selecting the operation to be performed by the function.
- Set up reference vector only.
- Generate variates using reference vector set up in a prior call to g05tec.
- Set up reference vector and generate variates.
- Generate variates without using the reference vector.
Constraint:
, , or .
-
2:
– Integer
Input
-
On entry: , the number of pseudorandom numbers to be generated.
Constraint:
.
-
3:
– Integer
Input
-
On entry: , the sample size of the hypergeometric distribution.
Constraint:
.
-
4:
– Integer
Input
-
On entry: , the population size of the hypergeometric distribution.
Constraint:
.
-
5:
– Integer
Input
-
On entry: , the number of specified items of the hypergeometric distribution.
Constraint:
.
-
6:
– double
Communication Array
-
On entry: if
, the reference vector from the previous call to
g05tec.
If
,
r is not referenced and may be
NULL.
On exit: if , the reference vector.
-
7:
– Integer
Input
-
On entry: the dimension of the array
r.
Suggested values:
- if , approximately;
- otherwise .
Constraints:
- if or , lr must not be too small, but the limit is too complicated to specify;
- if , lr must remain unchanged from the previous call to g05tec.
-
8:
– Integer
Communication Array
Note: the dimension,
, of this array is dictated by the requirements of associated functions that must have been previously called. This array MUST be the same array passed as argument
state in the previous call to
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.
-
9:
– Integer
Output
-
On exit: the pseudorandom numbers from the specified hypergeometric distribution.
-
10:
– NagError *
Input/Output
-
The NAG error argument (see
Section 7 in the Introduction to the NAG Library CL Interface).
Not applicable.
Background information to multithreading can be found in the
Multithreading documentation.
Please consult the
X06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this function. Please also consult the
Users' Note for your implementation for any additional implementation-specific information.
None.
The example program prints
pseudorandom integers from a hypergeometric distribution with
,
and
, generated by a single call to
g05tec, after initialization by
g05kfc.
None.