support overapproximate of unions instead of convex hulls

JuliaReach · Mar 9, 2024 · f02ccbe · f02ccbe
1 parent 985d938
commit f02ccbe
Showing 1 changed file with 24 additions and 9 deletions.
diff --git a/src/Approximations/overapproximate_zonotope.jl b/src/Approximations/overapproximate_zonotope.jl
@@ -112,8 +112,17 @@ constructed in the first phase.
     CAV 2009.
 """
 function overapproximate(X::ConvexHull{N,<:AbstractZonotope,<:AbstractZonotope},
-                         ::Type{<:Zonotope};
-                         algorithm="mean") where {N}
+                         ::Type{<:Zonotope}; algorithm="mean") where {N}
+    return _overapproximate_convex_hull_zonotope(X, algorithm)
+end
+
+function overapproximate(X::UnionSet{N,<:AbstractZonotope,<:AbstractZonotope},
+                         ::Type{<:Zonotope}; algorithm="mean") where {N}
+    return _overapproximate_convex_hull_zonotope(X, algorithm)
+end
+
+function _overapproximate_convex_hull_zonotope(X::ConvexHull{N,<:AbstractZonotope,<:AbstractZonotope},
+                                               ::Type{<:Zonotope}) where {N}
     # execute specific algorithm
     if algorithm == "mean"
         return _overapproximate_convex_hull_zonotope_G05(X)
@@ -124,7 +133,7 @@ function overapproximate(X::ConvexHull{N,<:AbstractZonotope,<:AbstractZonotope},
     end
 end
 
-function _overapproximate_convex_hull_zonotope_G05(ch::ConvexHull{N}) where {N}
+function _overapproximate_convex_hull_zonotope_G05(ch::LazySet{N}) where {N}
     # reduce to the same order if possible
     X, Y = first(ch), second(ch)
     m1, m2 = ngens(X), ngens(Y)
@@ -165,7 +174,7 @@ function _overapproximate_convex_hull_zonotope_G05(ch::ConvexHull{N}) where {N}
     return remove_zero_generators(Z)
 end
 
-function _overapproximate_convex_hull_zonotope_GGP09(ch::ConvexHull{N}) where {N}
+function _overapproximate_convex_hull_zonotope_GGP09(ch::LazySet{N}) where {N}
     Z1, Z2 = first(ch), second(ch)
     m = min(ngens(Z1), ngens(Z2))
     G1, G2 = genmat(Z1), genmat(Z2)
@@ -1071,16 +1080,22 @@ A zonotope overapproximation of the convex hull array of zonotopic sets.
 This method iteratively applies the overapproximation algorithm to the
 convex hull of two zonotopic sets from the given array of zonotopic sets.
 """
-function overapproximate(CHA::ConvexHullArray{N,<:AbstractZonotope},
-                         ::Type{<:Zonotope}) where {N}
-    arr = array(CHA)
+function overapproximate(CHA::ConvexHullArray{N,<:AbstractZonotope}, ::Type{<:Zonotope}) where {N}
+    return _overapproximate_union_zonotope(array(CHA))
+end
+
+function overapproximate(X::UnionSetArray{N,<:AbstractZonotope}, ::Type{<:Zonotope}) where {N}
+    return _overapproximate_union_zonotope(array(X))
+end
+
+function _overapproximate_union_zonotope(arr)
     n = length(arr)
     if n == 1
         return convert(Zonotope, arr[1])
     else
-        Zaux = overapproximate(ConvexHull(arr[1], arr[2]), Zonotope)
+        Zaux = overapproximate(UnionSet(arr[1], arr[2]), Zonotope)
         for k in 3:n
-            Zaux = overapproximate(ConvexHull(Zaux, arr[k]), Zonotope)
+            Zaux = overapproximate(UnionSet(Zaux, arr[k]), Zonotope)
         end
         return Zaux
     end