Conversion between set representations
This section of the manual lists the conversion functions between set representations.
Base.convert — Methodconvert(T::Type{HPOLYGON}, P::VPolygon) where {HPOLYGON<:AbstractHPolygon}Converts a polygon in vertex representation to a polygon in constraint representation.
Input
HPOLYGON– type used for dispatchP– polygon in vertex representation
Output
A polygon in constraint representation.
Base.convert — Methodconvert(::Type{Hyperrectangle}, H::AbstractHyperrectangle)Convert a hyperrectangular set to a hyperrectangle.
Input
Hyperrectangle– hyperrectangle type, used for dispatchH– hyperrectangular set
Output
A hyperrectangle.
Examples
julia> convert(Hyperrectangle, Interval(0.0, 1.0))
Hyperrectangle{Float64,Array{Float64,1},Array{Float64,1}}([0.5], [0.5])Base.convert — Methodconvert(::Type{Interval}, H::AbstractHyperrectangle)Converts a hyperrectangular set to an interval.
Input
Interval– interval type, used for dispatchH– hyperrectangular set
Output
An interval.
Examples
julia> convert(Interval, Hyperrectangle([0.5], [0.5]))
Interval{Float64,IntervalArithmetic.Interval{Float64}}([0, 1])Base.convert — Methodconvert(::Type{Interval}, S::LazySet{N}) where {N<:Real}Converts a convex set to an interval.
Input
Interval– interval type, used for dispatchS– convex set
Output
An interval.
Base.convert — Methodconvert(::Type{Hyperrectangle},
cpa::CartesianProductArray{N, HN}) where {N<:Real, HN<:AbstractHyperrectangle{N}}Converts the cartesian product of a finite number of hyperrectangular sets to a single hyperrectangle.
Input
Hyperrectangle– type used for dispatchS– cartesian product array of hyperrectangular set
Output
A hyperrectangle.
Algorithm
This implementation uses the center and radius_hyperrectangle methods of AbstractHyperrectangle.
Base.convert — Methodconvert(::Type{Hyperrectangle},
cpa::CartesianProductArray{N, Interval{N}}) where {N<:Real}Converts the cartesian product of a finite number of intervals to a single hyperrectangle.
Input
Hyperrectangle– type used for dispatchS– cartesian product array of intervals
Output
A hyperrectangle.
Algorithm
This implementation uses the min and max methods of Interval to reduce the allocatons and improve performance (see LazySets#1143).
Base.convert — Methodconvert(::Type{HPOLYGON}, H::AbstractHyperrectangle) where
{HPOLYGON<:AbstractHPolygon}Converts a hyperrectangular set to a polygon in constraint representation.
Input
HPOLYGON– type used for dispatchH– hyperrectangular set
Output
A polygon in constraint representation.
Base.convert — Methodconvert(::Type{HPOLYGON}, P::HPolytope{N, VN};
prune::Bool=true) where {N<:Real, VN<:AbstractVector{N}, HPOLYGON<:AbstractHPolygon}Convert from 2D polytope in H-representation to polygon in H-representation.
Input
type– target typeP– source polytope (must be 2D)prune– (optional, default:true) flag for removing redundant constraints in the end
Output
The 2D polytope represented as polygon.
Base.convert — Methodconvert(::Type{HPOLYGON}, S::AbstractSingleton{N}
) where {N<:Real, HPOLYGON<:AbstractHPolygon}Convert from singleton to polygon in H-representation.
Input
type– target typeS– singleton
Output
A polygon in constraint representation with the minimal number of constraints (three).
Base.convert — Methodconvert(::Type{HPOLYGON}, L::LineSegment{N}
) where {N<:Real, HPOLYGON<:AbstractHPolygon}Convert from line segment to polygon in H-representation.
Input
type– target typeL– line segmentprune– (optional, default:false) flag for removing redundant constraints in the end
Output
A flat polygon in constraint representation with the minimal number of constraints (four).
Base.convert — Methodconvert(::Type{HPOLYGON}, X::LazySet; [check_boundedness]::Bool=true) where {HPOLYGON<:AbstractHPolygon}Converts a polyhedral set to a polygon in vertex representation.
Input
PT– type used for dispatchX– setcheck_boundedness– (optional, defaulttrue) iftruecheck whether the setXis bounded before creating the polygon
Output
A polygon in constraint representation.
Algorithm
We compute the list of constraints of X, then instantiate the polygon.
Base.convert — Methodconvert(::Type{HPolyhedron}, P::AbstractPolytope)Convert a polytopic set to a polyhedron in H-representation.
Input
type– target typeP– source polytope
Output
The given polytope represented as a polyhedron in constraint representation.
Base.convert — Methodconvert(::Type{HPolytope}, P::AbstractHPolygon)Convert from polygon in H-representation to polytope in H-representation.
Input
type– target typeP– source polygon
Output
The polygon represented as 2D polytope.
Base.convert — Methodconvert(::Type{HPolytope}, H::AbstractHyperrectangle)Converts a hyperrectangular set to a polytope in constraint representation.
Input
HPolytope– type used for dispatchH– hyperrectangular set
Output
A polytope in constraint representation.
Base.convert — Methodconvert(::Type{HPolytope}, P::AbstractPolytope)Convert a polytopic set to a polytope in H-representation.
Input
type– target typeP– source polytope
Output
The given polytope represented as a polytope in constraint representation.
Algorithm
First the list of constraints of P is computed, then the corresponding HPolytope is created.
Base.convert — Methodconvert(::Type{HPolytope}, P::VPolytope)Convert from polytope in V-representation to polytope in H-representation.
Input
type– target typeP– source polytope
Output
The polytope in the dual representation.
Algorithm
The tohrep function is invoked. It requires the Polyhedra package.
Base.convert — Methodconvert(::Type{VPolygon}, P::AbstractHPolygon)Converts a polygon in constraint representation to a polygon in vertex representation.
Input
VPolygon– type used for dispatchP– polygon in constraint representation
Output
A polygon in vertex representation.
Base.convert — Methodconvert(::Type{VPolygon}, P::AbstractPolytope)Convert polytopic set to polygon in V-representation.
Input
type– target typeP– source polytope
Output
The 2D polytope represented as a polygon.
Base.convert — Methodconvert(::Type{VPolytope}, X::LazySet; [prune]::Bool=true)Generic conversion to polytope in vertex representation.
Input
type– target typeX– setprune– (optional, default:true) option to remove redundant vertices
Output
The given set represented as a polytope in vertex representation.
Algorithm
We compute the list of vertices of X and wrap the result in a polytope in vertex representation, VPolytope. Use the option prune to select whether or not to remove redundant vertices before constructing the polytope.
Base.convert — Methodconvert(::Type{VPolytope}, P::AbstractPolytope)Convert polytopic type to polytope in V-representation.
Input
type– target typeP– source polytope
Output
The set P represented as a VPolytope.
Base.convert — Methodconvert(::Type{VPolytope}, P::HPolytope)Convert from polytope in H-representation to polytope in V-representation.
Input
type– target typeP– source polytope
Output
The polytope in the dual representation.
Algorithm
The tovrep function is invoked. It requires the Polyhedra package.
Base.convert — Methodconvert(::Type{Zonotope}, Z::AbstractZonotope)Converts a zonotopic set to a zonotope.
Input
Zonotope– type, used for dispatchH– zonotopic set
Output
A zonotope.
Base.convert — Methodconvert(::Type{IntervalArithmetic.IntervalBox}, H::AbstractHyperrectangle)Converts a hyperrectangular set to an IntervalBox from IntervalArithmetic.
Input
IntervalBox– type used for dispatchH– hyperrectangular set
Output
An IntervalBox.
Base.convert — Methodconvert(::Type{Hyperrectangle}, IB::IntervalArithmetic.IntervalBox)Converts an IntervalBox from IntervalArithmetic to a hyperrectangular set.
Input
Hyperrectangle– type used for dispatchIB– interval box
Output
A Hyperrectangle.
Notes
IntervalArithmetic.IntervalBox uses static vectors to store each component interval, hence the resulting Hyperrectangle has its center and radius represented as a static vector (SArray).
Base.convert — Methodconvert(::Type{Zonotope}, cp::CartesianProduct{N, ZN1, ZN2}
) where {N<:Real, ZN1<:AbstractZonotope{N}, ZN2<:AbstractZonotope{N}}Converts the cartesian product of two zonotopes to a new zonotope.
Input
Zonotope– type used for dispatchS– cartesian product of two zonotopes
Output
A zonotope.
Algorithm
The cartesian product is obtained by:
- Concatenating the centers of each input zonotope.
- Arranging the generators in block-diagional fashion, and filled with zeros in the off-diagonal; for this reason, the generator matrix of the returned zonotope is built as a sparse matrix.
Base.convert — Methodconvert(::Type{Hyperrectangle},
cp::CartesianProduct{N, HN1, HN2}) where {N<:Real, HN1<:AbstractHyperrectangle{N}, HN2<:AbstractHyperrectangle{N}}Converts the cartesian product of two hyperrectangular sets to a single hyperrectangle.
Input
Hyperrectangle– type used for dispatchS– cartesian product of two hyperrectangular sets
Output
A hyperrectangle.
Algorithm
The result is obtained by concatenating the center and radius of each hyperrectangle. This implementation uses the center and radius_hyperrectangle methods of AbstractHyperrectangle.
Base.convert — Methodconvert(::Type{Zonotope}, cp::CartesianProduct{N, HN1, HN2}) where {N<:Real,
HN1<:AbstractHyperrectangle{N}, HN2<:AbstractHyperrectangle{N}}Converts the cartesian product of two hyperrectangular sets to a zonotope.
Input
Zonotope– type, used for dispatchcp– cartesian product of two hyperrectangular sets
Output
This method falls back to the conversion of the cartesian product to a single hyperrectangle, and then from a hyperrectangle to a zonotope.
Base.convert — Methodconvert(::Type{Zonotope}, cpa::CartesianProductArray{N, HN})
where {N<:Real, HN<:AbstractHyperrectangle{N}}Converts the cartesian product array of hyperrectangular sets to a zonotope.
Input
Zonotope– type, used for dispatchcpa– cartesian product array of hyperrectangular sets
Output
A zonotope.
Algorithm
This method falls back to the conversion of the cartesian product to a single hyperrectangle, and then from a hyperrectangle to a zonotope.
Base.convert — Methodconvert(::Type{Zonotope}, S::LinearMap{N, ZN}
) where {N, ZN<:AbstractZonotope{N}}Converts the lazy linear map of a zonotopic set to a zonotope.
Input
Zonotope– type, used for dispatchS– linear map of a zonotopic set
Output
A zonotope.
Algorithm
This method first applies the (concrete) linear map to the zonotopic set and then converts the result to a Zonotope type.
Base.convert — Methodconvert(::Type{Zonotope}, S::LinearMap{N, CartesianProduct{N, HN1, HN2}}
) where {N, HN1<:AbstractHyperrectangle{N},
HN2<:AbstractHyperrectangle{N}}Converts the lazy linear map of the cartesian product of two hyperrectangular sets to a zonotope.
Input
Zonotope– type, used for dispatchS– linear map of the cartesian product of hyperrectangular sets
Output
A zonotope.
Algorithm
This method first converts the cartesian product to a zonotope, and then applies the (concrete) linear map to the zonotope.
Base.convert — Methodconvert(::Type{Zonotope},S::LinearMap{N, CartesianProductArray{N, HN}}
) where {N, HN<:AbstractHyperrectangle{N}}Converts the lazy linear map of the cartesian product of a finite number of hyperrectangular sets to a zonotope.
Input
Zonotope– type, used for dispatchS– linear map of aCartesianProductArrayof hyperrectangular sets
Output
A zonotope.
Algorithm
This method first converts the cartesian product array to a zonotope, and then applies the (concrete) linear map to the zonotope.
Base.convert — Methodconvert(::Type{CartesianProduct{N, Interval{N}, Interval{N}}},
H::AbstractHyperrectangle{N}) where {N<:Real}Converts a two-dimensional hyperrectangle to the cartesian product of two intervals.
Input
CartesianProduct– type used for dispatchH– hyperrectangle
Output
The cartesian product of two intervals.
Base.convert — Methodconvert(::Type{CartesianProductArray{N, Interval{N}}},
H::AbstractHyperrectangle{N}) where {N<:Real}Converts a hyperrectangle to the cartesian product array of intervals.
Input
CartesianProductArray– type used for dispatchH– hyperrectangle
Output
The cartesian product of a finite number of intervals.
Base.convert — Methodconvert(::Type{Hyperrectangle}, r::Rectification{N, AH})
where {N<:Real, AH<:AbstractHyperrectangle{N}}Converts a rectification of a hyperrectangle to a hyperrectangle.
Input
Hyperrectangle– type used for dispatchr– rectification of a hyperrectangle
Output
A Hyperrectangle.
Base.convert — Methodconvert(::Type{Interval},
r::Rectification{N, IN}) where {N<:Real, IN<:Interval{N}}Converts a rectification of an interval to an interval.
Input
Interval– type used for dispatchr– rectification of an interval
Output
An Interval.
Base.convert — Methodconvert(::Type{IntervalArithmetic.Interval}, x::Interval)Converts a LazySets interval to an Interval from IntervalArithmetic.
Input
Interval– type used for dispatch, fromIntervalArithmeticx– interval (LazySets.Interval)
Output
An IntervalArithmetic.Interval.
Base.convert — Methodconvert(::Type{Interval}, x::IntervalArithmetic.Interval)Converts an Interval from IntervalArithmetic to an interval in LazySets.
Input
Interval– type used for dispatchx– interval (IntervalArithmetic.Interval)
Output
A LazySets.Interval.
Base.convert — Methodconvert(::Type{VPolytope},
X::ConvexHullArray{N, Singleton{N, VT}}) where {N, VT}Converts the convex hull array of singletons to a polytope in V-representation.
Input
VPolytope– type used for dispatchX– convex hull array of singletons
Output
A polytope in vertex representation.
Base.convert — Methodconvert(::Type{VPolygon},
X::ConvexHullArray{N, Singleton{N, VT}}) where {N, VT}Converts the convex hull array of singletons to a polygon in V-representation.
Input
VPolygon– type used for dispatchX– convex hull array of singletons
Output
A polygon in vertex representation.
Base.convert — Methodconvert(::Type{VPolygon}, X::LazySet)Generic conversion to polygon in vertex representation.
Input
type– target typeX– set
Output
The 2D set represented as a polygon.
Algorithm
We compute the list of vertices of X and wrap the result in a polygon in vertex representation, which guarantees that the vertices are sorted in counter-clockwise fashion.
Base.convert — Methodconvert(::Type{MinkowskiSumArray},
X::MinkowskiSum{N, ST, MinkowskiSumArray{N, ST}}) where {N, ST}Converts the Minkowski sum of a Minkowski sum array to a Minkowski sum array.
Input
MinkowskiSumArray– type used for dispatchX– Minkowski sum of a Minkowski sum array
Output
A Minkowski sum array.
Base.convert — Methodconvert(::Type{Interval}, x::MinkowskiSum{N, IT, IT}) where {N, IT<:Interval{N}}Converts the Minkowski sum of two intervals into an interval.
Input
Interval– type used for dispatchx– Minkowski sum of a pair of intervals
Output
An interval.
Base.convert — Methodconvert(::Type{HParallelotope}, Z::AbstractZonotope{N}) where {N}Converts a zonotopic set of order one into a parallelotope in constraint representation.
Input
HParallelotope– type used for dispatchZ– zonotopic set
Output
A parallelotope in constraint representation.
Notes
This function requires that the list of constraints of Z are obtained in the particular order returned from the constraints list function of a Zonotope.
Base.convert — Methodconvert(::Type{Zonotope}, cp::CartesianProduct{N, AZ1, AZ2}) where
{N, AZ1<:AbstractZonotope{N}, AZ2<:AbstractZonotope{N}}Converts a cartesian product of two zonotopes into a zonotope.
Input
Zonotope– type used for dispatchcp– cartesian product of two zonotopes
Output
A zonotope.
Notes
This implementation creates a Zonotope with sparse vector and matrix representation.
Base.convert — Methodconvert(::Type{Zonotope}, cpa::CartesianProductArray{N, AZ})
where {N, AZ<:AbstractZonotope{N}}Converts a cartesian product array of zonotopes into a zonotope.
Input
Zonotope– type used for dispatchcpa– cartesian product array of zonotopes
Output
A zonotope.
Notes
This function requires the use of SparseArrays.