.. include:: replace.txt Data Collection --------------- This chapter describes the ns-3 Data Collection Framework (DCF), which provides capabilities to obtain data generated by models in the simulator, to perform on-line reduction and data processing, and to marshal raw or transformed data into various output formats. The framework presently supports standalone ns-3 runs that don't rely on any external program execution control. The objects provided by the DCF may be hooked to |ns3| trace sources to enable data processing. The source code for the classes lives in the directory ``src/stats``. This chapter is organized as follows. First, an overview of the architecture is presented. Next, the helpers for these classes are presented; this initial treatment should allow basic use of the data collection framework for many use cases. Users who wish to produce output outside of the scope of the current helpers, or who wish to create their own data collection objects, should read the remainder of the chapter, which goes into detail about all of the basic DCF object types and provides low-level coding examples. .. toctree:: :maxdepth: 1 data-collection-overview.rst data-collection-helpers.rst probe.rst collector.rst aggregator.rst adaptor.rst scope-and-limitations.rst