NeticaRNG-class {RNetica}R Documentation

Class "NeticaRNG"

Description

This is an object containing a reference to a Netica Random Number Generator. Note that the storage for NeticaRNG objects should be freed when you are done with them by calling FreeNeticaRNG(rng).

Details

Netica supports random number generator objects which serve can be used to generate random cases (GenerateRandomCase()). In either case explicitly creating a random number generator is optional. If this is not done, the default random number generator is uses, which is slightly slower because it needs to be threadsafe. As RNetica probably adds more overhead than the non-threadsafe RNG, the primary use for creating a NeticaRNG is to produce a reproducable sequence of random cases.

Creating a random number generator with rng <- NewNeticaRNG(seed) generates an object in Netica space. The memory for that object should be freed when that is complete. The expression FreeNeticaRNG(rng) frees this object. The function WithRNG can be used to execute code in a context where the RNG will be freed after after completion or in the case of early termination due to an error.

When the random number generator is freed, or if the R session or Netica session is terminated, the NeticaRNG object will become inactive. The function isNeticaRNGActive(rng) tests to see if the random number generator is active (the Netica version still exists).

Extends

All reference classes extend and inherit methods from "envRefClass". Note that because this is a reference class unlike traditional S3 and S4 classes it can be destructively modified. Also fields (slots) are accessed using the ‘$’ operator.

Methods

print

signature(x = "NeticaRNG"): Produces a printer representation of the RNG object.

toString

signature(x = "NeticaRNG"): Produces a string representation of the RNG object.

Fields

Note these should be regarded as read-only from user code.

Name:

Object of class character giving a name to the RNG. These are autogenerated with a number.

Session:

Object of class NeticaSession : a back pointer to the NeticaSession object in which the network was created.

Netica_RNG:

Object of class externalptr which hold the pointer to the RNG object in the Netica workspace.

Seed:

Object of class integer giving the seed used to initialize the RNG.

Class-Based Methods

show():

Provides a printed description

free():

Frees the RNG in Netica Memory. Equivalent to FreeNeticaRNG.

isActive():

Test to see if the RNG is active (been created in Netica) or inactive (already freed).

clearErrors(severity):

Calls clearErrors on the Session object.

reportErrors(maxreport, clear):

Calls reportErrors on the Session object.

initialize(Name, Session, Seed, ...):

Initialization function. Should not be called by user code.

Note

There are two other uses of newly created Netica RNG objects in the Netica Manual which are not currently supported by RNetica. One is to simply generate uniform random numbers which seems superfluous given R's richer random number generation facilities. The second it to associate the RNG with a network. According to the manual, such RNGs no longer need to be deleted when you are done with them. This seems like it could lead to a situation where a single RNG was associated with two networks and then the RNG was deleted when the first network was deleted. Therefore the function NetworkSetRNG() always creates a new RNG.

Internally, a weak reference system is used to keep a list of Netica RNG objects which need to be closed when RNetica is unloaded. RNG objects should also be forced closed when garbage collected. The weak reference system is somewhat experimental, so well designed code should manually close the RNG when the program is through with it.

Author(s)

Russell Almond

References

http://norsys.com/onLineAPIManual/index.html: NewRandomGenerator_ns(), DeleteRandomGen_ns() http://homepage.stat.uiowa.edu/~luke/R/references/weakfinex.html

See Also

An object of NeticaRNG which is produced by a call to NewNeticaRNG.

NetworkSetRNG(), GenerateRandomCase()

Examples


sess <- NeticaSession()
startSession(sess)

rng <- NewNeticaRNG(123456789,sess)

stopifnot(is.NeticaRNG(rng),
          isNeticaRNGActive(rng))

FreeNeticaRNG(rng)
stopifnot(!isNeticaRNGActive(rng))

stopSession(sess)



[Package RNetica version 0.5-4 Index]