Minor chnages

Author: albertomercurio

CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/qutip/QuantumToolbox.jl/tree/main)
 
-- Support different length for to and from on GeneralDimensions. ([#448])
+- Support different length for `to` and `from` on GeneralDimensions. ([#448])
 
 ## [v0.30.0]
 Release date: 2025-04-12

src/entropy.jl

@@ -149,11 +149,11 @@ Here, ``S`` is the [Von Neumann entropy](https://en.wikipedia.org/wiki/Von_Neuma
 - `kwargs` are the keyword arguments for calculating Von Neumann entropy. See also [`entropy_vn`](@ref).
 """
 function entropy_mutual(
-    ρAB::QuantumObject{ObjType,<:AbstractDimensions{N,M}},
+    ρAB::QuantumObject{ObjType,<:AbstractDimensions{N,N}},
     selA::Union{Int,AbstractVector{Int},Tuple},
     selB::Union{Int,AbstractVector{Int},Tuple};
     kwargs...,
-) where {ObjType<:Union{KetQuantumObject,OperatorQuantumObject},N,M}
+) where {ObjType<:Union{KetQuantumObject,OperatorQuantumObject},N}
     # check if selA and selB matches the dimensions of ρAB
     sel_A_B = (selA..., selB...)
     (length(sel_A_B) != N) && throw(

src/qobj/dimensions.jl

@@ -4,7 +4,7 @@ This file defines the Dimensions structures, which can describe composite Hilber
 
 export AbstractDimensions, Dimensions, GeneralDimensions
 
-abstract type AbstractDimensions{N,M} end
+abstract type AbstractDimensions{M,N} end
 
 @doc raw"""
     struct Dimensions{N,T<:Tuple} <: AbstractDimensions{N, N}
@@ -42,14 +42,14 @@ Dimensions(dims::Any) = throw(
 
 A structure that describes the left-hand side (`to`) and right-hand side (`from`) Hilbert [`Space`](@ref) of an [`Operator`](@ref).
 """
-struct GeneralDimensions{N,M,T1<:Tuple,T2<:Tuple} <: AbstractDimensions{N,M}
+struct GeneralDimensions{M,N,T1<:Tuple,T2<:Tuple} <: AbstractDimensions{M,N}
     # note that the number `N` should be the same for both `to` and `from`
     to::T1   # space acting on the left
     from::T2 # space acting on the right
 
     # make sure the elements in the tuple are all AbstractSpace
-    GeneralDimensions(to::NTuple{N,T1}, from::NTuple{M,T2}) where {N,M,T1<:AbstractSpace,T2<:AbstractSpace} =
-        new{N,M,typeof(to),typeof(from)}(to, from)
+    GeneralDimensions(to::NTuple{M,T1}, from::NTuple{N,T2}) where {M,N,T1<:AbstractSpace,T2<:AbstractSpace} =
+        new{M,N,typeof(to),typeof(from)}(to, from)
 end
 function GeneralDimensions(dims::Union{AbstractVector{T},NTuple{N,T}}) where {T<:Union{AbstractVector,NTuple},N}
     (length(dims) != 2) && throw(ArgumentError("Invalid dims = $dims"))
@@ -59,9 +59,8 @@ function GeneralDimensions(dims::Union{AbstractVector{T},NTuple{N,T}}) where {T<
 
     L1 = length(dims[1])
     L2 = length(dims[2])
-    ((L1 > 0) && (L2 > 0)) || throw(
-        DomainError((L1, L2), "The length of the arguments `dims[1]` and `dims[2]` must have at least one element."),
-    )
+    (L1 > 0) || throw(DomainError(L1, "The length of `dims[1]` must be larger or equal to 1."))  
+    (L2 > 0) || throw(DomainError(L2, "The length of `dims[2]` must be larger or equal to 1.")) 
 
     return GeneralDimensions(Tuple(Space.(dims[1])), Tuple(Space.(dims[2])))
 end

src/qobj/quantum_object_base.jl

@@ -274,13 +274,13 @@ get_dimensions_to(
 
 # this returns `from` in GeneralDimensions representation
 get_dimensions_from(A::AbstractQuantumObject{KetQuantumObject,<:Dimensions{N}}) where {N} = space_one_list(N)
-get_dimensions_from(A::AbstractQuantumObject{BraQuantumObject,<:Dimensions{N}}) where {N} = A.dimensions.to
-get_dimensions_from(A::AbstractQuantumObject{OperatorQuantumObject,<:Dimensions{N}}) where {N} = A.dimensions.to
-get_dimensions_from(A::AbstractQuantumObject{OperatorQuantumObject,<:GeneralDimensions{N,M}}) where {N,M} =
+get_dimensions_from(A::AbstractQuantumObject{BraQuantumObject,<:Dimensions}) = A.dimensions.to
+get_dimensions_from(A::AbstractQuantumObject{OperatorQuantumObject,<:Dimensions}) = A.dimensions.to
+get_dimensions_from(A::AbstractQuantumObject{OperatorQuantumObject,<:GeneralDimensions}) =
     A.dimensions.from
 get_dimensions_from(
-    A::AbstractQuantumObject{ObjType,<:Dimensions{N}},
-) where {ObjType<:Union{SuperOperatorQuantumObject,OperatorBraQuantumObject,OperatorKetQuantumObject},N} =
+    A::AbstractQuantumObject{ObjType,<:Dimensions},
+) where {ObjType<:Union{SuperOperatorQuantumObject,OperatorBraQuantumObject,OperatorKetQuantumObject}} =
     A.dimensions.to
 
 # functions for getting Float or Complex element type