DFG Data Structures

DFG Data Structures

Variables and factors can potentially contain a lot of data, so DFG has different structures that are specialized for each use-case and level of detail. For example, if you want to retrieve just a simple summary of the structure, you can use the summary or skeleton structures to identify variables and factors of interest and then retrieve more detail on the subset.

Note that not all drivers support all of the structures.

The following section discusses the datastructures for each level. A quick summary of the types and the available properties (some of which are derived) is provided below.

Accessible properties for each of the variable structures:

LabelTimestampTagsEstimatesSoft TypeSolvableSolver DataSmall DataBig Data Entries
SkeletonDFGVariableXX
DFGVariableSummaryXXXXSymbolX
DFGVariableXXXXXXXXX

Accessible properties for each of the factor structures:

LabelTimestampTagsFactor TypeSolvableSolver Data
SkeletonDFGFactorXX
DFGFactorSummaryXXX
DFGFactorXXXXXX

DFG Skeleton

DFG Summary

Full DFG Node

Additional Offloaded Data

Additional, larger data can be associated with variables using keyed big data entries.