allow arbitrary eltype (#33)

cc @kahaaga in complexutymeasures we need this. I am updating the whole ecosystem to SSSets v2, which takes my whole sunday. GODDAMNIT

CHANGELOG.md

@@ -1,8 +1,13 @@
 Changelog for StateSpaceSets.jl is kept w.r.t. version 1.3
 
+# 2.1
+
+It is allowed to make `StateSpaceSet` with points of arbitrary `eltype` now.
+Please don't use `Complex` numbers as the `eltype`!
+
 # 2.0
 
-- `StateSpaceSet` now subtypes `AbstractVector`, in particular `StateSpaceSet{V<:AbstractVector} <: AbstractVector{V}`. This leads to the breaking change that `size(ssset) = (length(ssset), )` while before `size` was `length(ssset), dimension(ssset)`. Now you have to use `dimension(ssset)` exclusively to get the "number of columns" in the state space set.
+- `StateSpaceSet` now subtypes `AbstractVector`, in particular `StateSpaceSet{V<:AbstractVector} <: AbstractVector{V}`. This leads to the breaking change that `size(ssset) = (length(ssset), )` while before `size` was `(length(ssset), dimension(ssset))`. Now you have to use `dimension(ssset)` exclusively to get the "number of columns" in the state space set.
 - `StateSpaceSet` now supports arbitrary inner vectors as state space points.
   The keyword `container` can be given to all functions that make state space sets
   and sets the type of the container of the inner vectors. This is the abstract type

Project.toml

@@ -2,7 +2,7 @@ name = "StateSpaceSets"
 uuid = "40b095a5-5852-4c12-98c7-d43bf788e795"
 authors = ["George Datseris <[email protected]>"]
 repo = "https://github.com/JuliaDynamics/StateSpaceSets.jl.git"
-version = "2.0.1"
+version = "2.1.0"
 
 [deps]
 Distances = "b4f34e82-e78d-54a5-968a-f98e89d6e8f7"

src/statespaceset.jl

@@ -10,7 +10,7 @@ export cov, cor, mean_and_cov
 # D = dimension, T = element type, V = container type
 # note that the container type is given as keyword `container` to
 # all functions that somehow end up making a state space set.
-abstract type AbstractStateSpaceSet{D, T<:Real, V} <: AbstractVector{V} end
+abstract type AbstractStateSpaceSet{D, T, V} <: AbstractVector{V} end
 
 # Core extensions and functions:
 """

src/statespaceset_concrete.jl

@@ -1,11 +1,11 @@
 export StateSpaceSet
 
 """
-    StateSpaceSet{D, T<:Real, V} <: AbstractVector{V}
+    StateSpaceSet{D, T, V} <: AbstractVector{V}
 
 A dedicated interface for sets in a state space.
 It is an **ordered container of equally-sized points** of length `D`,
-with element type `T<:Real`,
+with element type `T`,
 represented by a vector of type `V`. Typically `V` is `SVector{D,T}` or `Vector{T}`
 and the data are always stored internally as `Vector{V}`.
 
@@ -86,7 +86,7 @@ end
 ###########################################################################
 # StateSpaceSet(Vectors of stuff)
 ###########################################################################
-function StateSpaceSet(vecs::AbstractVector{T}...; container = SVector) where {T<:Real}
+function StateSpaceSet(vecs::AbstractVector{T}...; container = SVector) where {T}
     data = _ssset(vecs...)
     if container != SVector
         data = container.(data)
@@ -96,7 +96,7 @@ function StateSpaceSet(vecs::AbstractVector{T}...; container = SVector) where {T
     return StateSpaceSet{D,T,V}(data)
 end
 
-@generated function _ssset(vecs::AbstractVector{T}...) where {T<:Real}
+@generated function _ssset(vecs::AbstractVector{T}...) where {T}
     D = length(vecs)
     gens = [:(vecs[$k][i]) for k=1:D]
     quote

test/ssset_tests.jl

@@ -30,11 +30,13 @@ s = StateSpaceSet(o)
     @test m3[1] isa MVector
   end
 
-  @testset "not reals" begin
-    q = fill("a", 10)
-    @test_throws MethodError StateSpaceSet(q)
+  @testset "nonreal element" begin
+    ff = fill("ff", 10)
+    tt = fill("tt", 10)
+    ss = StateSpaceSet(ff, tt)
+    @test dimension(ss) == 2
+    @test eltype(ss) == String
   end
-
 end