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DistributedFactorGraphs Types

DistributedFactorGraphs Module

DistributedFactorGraphs.DistributedFactorGraphs — Module

DistributedFactorGraphs.jl provides a flexible factor graph API for use in the Caesar.jl ecosystem.

The package supplies:

  • A standardized API for interacting with factor graphs
  • Implementations of the API for in-memory and database-driven operation
  • Visualization extensions to validate the underlying graph
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Types

Abstract DFG

Summary DFG

DFG Variable Nodes

DistributedFactorGraphs.PackedState — Type
mutable struct PackedState

Packed State structure for serializing DFGVariables.

Fields:

  • id::Union{Nothing, Base.UUID}

  • vecval::Vector{Float64}

  • dimval::Int64

  • vecbw::Vector{Float64}

  • dimbw::Int64

  • BayesNetOutVertIDs::Vector{Symbol}

  • dimIDs::Vector{Int64}

  • dims::Int64

  • eliminated::Bool

  • BayesNetVertID::Symbol

  • separator::Vector{Symbol}

  • variableType::String

  • initialized::Bool

  • infoPerCoord::Vector{Float64}

  • ismargin::Bool

  • dontmargin::Bool

  • solveInProgress::Int64

  • solvedCount::Int64

  • solveKey::Symbol

  • covar::Vector{Float64}

  • _version::VersionNumber

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DistributedFactorGraphs.State — Type
mutable struct State{T<:AbstractStateType, P, N}

Data container for solver-specific data.

T: Variable type, such as Position1, or RoME.Pose2, etc. P: Variable point type, the type of the manifold point. N: Manifold dimension. Fields:

  • id::Union{Nothing, Base.UUID}: Globally unique identifier.
  • val::Vector: Vector of on-manifold points used to represent a ManifoldKernelDensity (or parametric) belief.
  • bw::Matrix{Float64}: Common kernel bandwith parameter used with ManifoldKernelDensity, see field covar for the parametric covariance.

  • covar::Array{StaticArraysCore.SMatrix{N, N, Float64}, 1} where N: Parametric (Gaussian) covariance.

  • BayesNetOutVertIDs::Vector{Symbol}

  • dimIDs::Vector{Int64}

  • dims::Int64

  • eliminated::Bool: Flag used by junction (Bayes) tree construction algorithm to know whether this variable has yet been included in the tree construction.

  • BayesNetVertID::Symbol

  • separator::Vector{Symbol}

  • initialized::Bool: False if initial numerical values are not yet available or stored values are not ready for further processing yet.

  • infoPerCoord::Vector{Float64}: Stores the amount information (per measurement dimension) captured in each coordinate dimension.
  • ismargin::Bool: Should this variable solveKey be treated as marginalized in inference computations.
  • dontmargin::Bool: Should this variable solveKey always be kept fluid and not be automatically marginalized.
  • solveInProgress::Int64: Convenience flag on whether a solver is currently busy working on this variable solveKey.
  • solvedCount::Int64: How many times has a solver updated this variable solveKey estimte.
  • solveKey::Symbol: solveKey identifier associated with this State object.
  • events::Dict{Symbol, Base.GenericCondition{ReentrantLock}}: Future proofing field for when more multithreading operations on graph nodes are implemented, these conditions are meant to be used for atomic write transactions to this VND.
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DistributedFactorGraphs.VariableCompute — Type
struct VariableCompute{T<:AbstractStateType, P, N} <: AbstractGraphVariable

Complete variable structure for a DistributedFactorGraph variable.

Fields:

  • id::Union{Nothing, Base.UUID}: The ID for the variable

  • label::Symbol: Variable label, e.g. :x1. Accessor: getLabel

  • timestamp::TimeZones.ZonedDateTime: Variable timestamp. Accessors: getTimestamp, setTimestamp

  • nstime::Dates.Nanosecond: Nanoseconds since a user-understood epoch (i.e unix epoch, robot boot time, etc.)

  • tags::Set{Symbol}: Variable tags, e.g [:POSE, :VARIABLE, and :LANDMARK]. Accessors: getTags, mergeTags!, and removeTags!

  • ppeDict::Dict{Symbol, AbstractPointParametricEst}: Dictionary of parametric point estimates keyed by solverDataDict keys Accessors: addPPE!, updatePPE!, and deletePPE!

  • solverDataDict::Dict{Symbol, State{T, P, N}} where {T<:AbstractStateType, P, N}: Dictionary of solver data. May be a subset of all solutions if a solver label was specified in the get call. Accessors: addState!, mergeState!, and deleteState!

  • smallData::Dict{Symbol, Union{Bool, Float64, Int64, Vector{Bool}, Vector{Float64}, Vector{Int64}, Vector{String}, String}}: Dictionary of small data associated with this variable. Accessors: getMetadata, setMetadata!

  • dataDict::Dict{Symbol, Blobentry}: Dictionary of large data associated with this variable. Accessors: addBlobentry!, getBlobentry, mergeBlobentry!, and deleteBlobentry!

  • solvable::Base.RefValue{Int64}: Solvable flag for the variable. Accessors: getSolvable, setSolvable!

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DistributedFactorGraphs.VariableDFG — Type
struct VariableDFG <: AbstractGraphVariable

The Variable information packed in a way that accomdates multi-lang using json.

Notes:

  • timestamp is a ZonedDateTime in UTC.
  • nstime can be used as mission time, with the convention that the timestamp millis coincide with the mission start nstime
    • e.g. timestamp is 2020-01-01 06:30:01.250 UTC and first nstime is 250_000_000.
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DistributedFactorGraphs.VariableSummary — Type
struct VariableSummary <: AbstractGraphVariable

Summary variable structure for a DistributedFactorGraph variable.

Fields:

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DFG Factor Nodes

DistributedFactorGraphs.FactorCompute — Type
struct FactorCompute{FT<:AbstractObservation, N} <: AbstractGraphFactor

Complete factor structure for a DistributedFactorGraph factor.

DevNotes

  • TODO make consistent the order of fields skeleton Skeleton, Summary, thru FactorCompute

    • e.g. timestamp should be a later field.

Fields:

  • id::Union{Nothing, Base.UUID}: The ID for the factor

  • label::Symbol: Factor label, e.g. :x1f1. Accessor: getLabel

  • tags::Set{Symbol}: Factor tags, e.g [:FACTOR]. Accessors: getTags, mergeTags!, and removeTags!

  • _variableOrderSymbols::Tuple{Vararg{Symbol, N}} where N: Internal cache of the ordering of the neighbor variables. Rather use getVariableOrder to get the list as this is an internal value. Accessors: getVariableOrder

  • timestamp::TimeZones.ZonedDateTime: Variable timestamp. Accessors: getTimestamp, setTimestamp

  • nstime::Dates.Nanosecond: Nano second time

  • solvable::Base.RefValue{Int64}: Solvable flag for the factor. Accessors: getSolvable, setSolvable!

  • smallData::Dict{Symbol, Union{Bool, Float64, Int64, Vector{Bool}, Vector{Float64}, Vector{Int64}, Vector{String}, String}}: Dictionary of small data associated with this variable. Accessors: getMetadata, setMetadata!

  • observation::AbstractObservation: Observation function or measurement for this factor. Accessors: getObservation(@ref)

  • state::DistributedFactorGraphs.FactorState: Describes the current state of the factor. Persisted in serialization. Accessors: getFactorState

  • solvercache::Base.RefValue{<:AbstractFactorCache}: Temporary, non-persistent memory used internally by the solver for intermediate numerical computations and buffers. solvercache is lazily allocated and only used during factor operations; it is not serialized or retained after solving. Accessors: getCache, setCache!

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DistributedFactorGraphs.FactorSkeleton — Type
struct FactorSkeleton <: AbstractGraphFactor

Skeleton factor structure for a DistributedFactorGraph factor.

Fields:

  • id::Union{Nothing, Base.UUID}: The ID for the factor

  • label::Symbol: Factor label, e.g. :x1f1. Accessor: getLabel

  • tags::Set{Symbol}: Factor tags, e.g [:FACTOR]. Accessors: getTags, mergeTags!, and removeTags!

  • _variableOrderSymbols::Vector{Symbol}: Internal cache of the ordering of the neighbor variables. Rather use listNeighbors to get the list as this is an internal value. Accessors: getVariableOrder

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DistributedFactorGraphs.FactorSummary — Type
struct FactorSummary <: AbstractGraphFactor

Read-only summary factor structure for a DistributedFactorGraph factor.

Fields:

  • id::Union{Nothing, Base.UUID}: The ID for the factor

  • label::Symbol: Factor label, e.g. :x1f1. Accessor: getLabel

  • tags::Set{Symbol}: Factor tags, e.g [:FACTOR]. Accessors: getTags, mergeTags!, and removeTags!

  • _variableOrderSymbols::Vector{Symbol}: Internal cache of the ordering of the neighbor variables. Rather use listNeighbors to get the list as this is an internal value. Accessors: getVariableOrder

  • timestamp::TimeZones.ZonedDateTime: Variable timestamp. Accessors: getTimestamp

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Error Types

DFG Plots [GraphMakie.jl]

DistributedFactorGraphs.plotDFG — Function

Plots the structure of the factor graph. GraphMakie must be imported before DistributedFactorGraphs for these functions to be available. Returns the plot context.

E.g.

using GraphMakie
using DistributedFactorGraphs
# ... Make graph...
plotDFG(fg)

More information at GraphMakie.jl

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Drivers

GraphsDFGs

FileDFG

DistributedFactorGraphs.loadDFG! — Method
loadDFG!(dfgLoadInto, dst; overwriteDFGMetadata)

Load a DFG from a saved folder.

Example

using DistributedFactorGraphs, IncrementalInference
# Create a DFG - can make one directly, e.g. GraphsDFG{NoSolverParams}() or use IIF:
dfg = initfg()
# Load the graph
loadDFG!(dfg, "/tmp/savedgraph.tar.gz")
# Use the DFG as you do normally.
ls(dfg)

See also: loadDFG, saveDFG

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DistributedFactorGraphs.saveDFG — Method
saveDFG(folder, dfg; saveMetadata)

Save a DFG to a folder. Will create/overwrite folder if it exists.

DevNotes:

  • TODO remove compress kwarg.

Example

using DistributedFactorGraphs, IncrementalInference
# Create a DFG - can make one directly, e.g. GraphsDFG{NoSolverParams}() or use IIF:
dfg = initfg()
# ... Add stuff to graph using either IIF or DFG:
v1 = addVariable!(dfg, :a, ContinuousScalar, tags = [:POSE], solvable=0)
# Now save it:
saveDFG(dfg, "/tmp/saveDFG.tar.gz")
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