Bug 831

Summary:	Insufficient numerical precision of timestamped simulation time in the ascii trace file (ns-3.7)
Product:	ns-3	Reporter:	Jakub Konka <jakub.konka>
Component:	core	Assignee:	Craig Dowell <craigdo>
Status:	RESOLVED INVALID
Severity:	normal	CC:	craigdo, ns-bugs
Priority:	P5
Version:	ns-3.7
Hardware:	PC
OS:	Linux

Description Jakub Konka 2010-03-03 18:36:51 UTC

Overview:
The simulation time expressed in seconds and timestamped in the ascii trace file has insufficient numerical precision, and can cause erroneous results especially for high-speed wired data networks. 

Compare with bug 830 http://www.nsnam.org/bugzilla/﷒0﷓

The only difference between the two bugs is in the underlying NS3 modules: in ns-3-dev OutputStreamWrapper was responsible, in ns-3.7 AsciiWriter is.

In AsciiWriter module case, the bug can be fixed in exactly the same way as in OutputStreamWrapper (see bug 830 http://www.nsnam.org/bugzilla/﷒1﷓ ).

Comment 1 Craig Dowell 2010-04-07 14:45:49 UTC

With the new tracing framework, a user can set the floating point precision of the underlying stream to whatever is required.

  AsciiTraceHelper helper;
  Ptr<OutputStreamWrapper> stream = helper.CreateFileStream ("file");
  stream->GetStream ()->precision (8);

Does that meet your needs?