[Repast-developer] [ repast-Bugs-1707054 ] NetworkFactory, NetUtilities Random initialization needed

[SourceForge.net <no...@so...>]

Bugs item #1707054, was opened at 2007-04-24 19:41
Message generated for change (Tracker Item Submitted) made by Item Submitter
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=101703&aid=1707054&group_id=1703

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Repast J
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: NetworkFactory, NetUtilities Random initialization needed

Initial Comment:
NetworkFactory, NetUtilities Random initialization needed

Several methods in
uchicago.src.sim.network.NetworkFactory make calls to
uchicago.src.sim.network.NetUtilities.randomRewire or
uchicago.src.sim.network.NetUtilities.randomRewireSymmetric.

These NetUtilities methods use
uchicago.src.sim.util.Random to generate random
numbers. For example, NetUtilities.randomRewire calls
Random.uniform.nextDoubleFromTo.

The documentation for uchicago.src.sim.util.Random
states:

  "Before using any of the instance variable
  distributions, these distributions must be created
  via the appropriate create* method."

However, the instance variable distributions don't seem
to be intialized within the NetUtilities class for use
by its static methods.

This means that if one calls certain NetworkFactory
methods such as createWattsStrogatzNetwork (as I did)
without first manually creating
uchicago.src.sim.util.Random.uniform, then one gets a
strange, very difficult to track down
NullPointerException when NetUtilities.randomRewire
calls Random.uniform.nextDoubleFromTo and finds no
Random.uniform object (see line 726 of NetUtilities).

The workaround, of course, is to manually create the
required distribution in user code using, e.g.,
uchicago.src.sim.util.Random.createUniform().

Neither the origin this strange Exception nor the need
to manually create the distribution are documented in
the NetworkFactory or NetUtilities classes.

I'm filing a bug in part as documentation of this
issue, hopefully to save others some time in tracking
this down and working around it.


----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=101703&aid=1707054&group_id=1703