fix rng reproducibility

Author: ytdHuang

docs/src/users_guide/time_evolution/solution.md

@@ -104,7 +104,7 @@ We also provide the following functions for statistical analysis of multi-trajec
 | [`average_expect(sol)`](@ref average_expect) | Return the trajectory-averaged expectation values at each time point. |
 | [`std_expect(sol)`](@ref std_expect) | Return the trajectory-wise standard deviation of the expectation values at each time point. |
 
-Multi-trajectory solutions also keep the random number generator (`rng`) to allow recomputing the results:
+Multi-trajectory solutions also keep the initial random number generator (`rng`) to allow recomputing the results:
 
 ```julia
 rng = sol.rng # this can be specified as a keyword argument (`rng = rng`) to the solvers

src/time_evolution/mcsolve.jl

@@ -235,7 +235,10 @@ function mcsolveEnsembleProblem(
     output_func::Union{Tuple,Nothing} = nothing,
     kwargs...,
 ) where {TJC<:LindbladJumpCallbackType}
-    _prob_func = isnothing(prob_func) ? _ensemble_dispatch_prob_func(rng, ntraj, tlist, _mcsolve_prob_func) : prob_func
+    copied_rng = copy(rng) # use the copied rng, and keep the initial one to pass it directly to solution later
+
+    _prob_func =
+        isnothing(prob_func) ? _ensemble_dispatch_prob_func(copied_rng, ntraj, tlist, _mcsolve_prob_func) : prob_func
     _output_func =
         output_func isa Nothing ?
         _ensemble_dispatch_output_func(ensemblealg, progress_bar, ntraj, _mcsolve_output_func) : output_func
@@ -247,7 +250,7 @@ function mcsolveEnsembleProblem(
         c_ops;
         e_ops = e_ops,
         params = params,
-        rng = rng,
+        rng = copied_rng,
         jump_callback = jump_callback,
         kwargs...,
     )

src/time_evolution/smesolve.jl

@@ -239,10 +239,12 @@ function smesolveEnsembleProblem(
     store_measurement::Union{Val,Bool} = Val(false),
     kwargs...,
 ) where {StateOpType<:Union{Ket,Operator,OperatorKet}}
+    copied_rng = copy(rng) # use the copied rng, and keep the initial one to pass it directly to solution later
+
     _prob_func =
         isnothing(prob_func) ?
         _ensemble_dispatch_prob_func(
-            rng,
+            copied_rng,
             ntraj,
             tlist,
             _stochastic_prob_func;
@@ -261,7 +263,7 @@ function smesolveEnsembleProblem(
         sc_ops;
         e_ops = e_ops,
         params = params,
-        rng = rng,
+        rng = copied_rng,
         progress_bar = Val(false),
         store_measurement = makeVal(store_measurement),
         kwargs...,

src/time_evolution/ssesolve.jl

@@ -233,10 +233,12 @@ function ssesolveEnsembleProblem(
     store_measurement::Union{Val,Bool} = Val(false),
     kwargs...,
 )
+    copied_rng = copy(rng) # use the copied rng, and keep the initial one to pass it directly to solution later
+
     _prob_func =
         isnothing(prob_func) ?
         _ensemble_dispatch_prob_func(
-            rng,
+            copied_rng,
             ntraj,
             tlist,
             _stochastic_prob_func;
@@ -254,7 +256,7 @@ function ssesolveEnsembleProblem(
         sc_ops;
         e_ops = e_ops,
         params = params,
-        rng = rng,
+        rng = copied_rng,
         progress_bar = Val(false),
         store_measurement = makeVal(store_measurement),
         kwargs...,

src/time_evolution/time_evolution.jl

@@ -103,7 +103,7 @@ A structure storing the results and some information from solving quantum trajec
 - `times::AbstractVector`: The time list of the evolution.
 - `states::Vector{Vector{QuantumObject}}`: The list of result states in each trajectory and each time point in `times`.
 - `expect::Union{AbstractArray,Nothing}`: The expectation values corresponding to each trajectory and each time point in `times`.
-- `rng::AbstractRNG`: Random number generator for reproducibility.
+- `rng::AbstractRNG`: Initial random number generator for reproducibility.
 - `col_times::Vector{Vector{Real}}`: The time records of every quantum jump occurred in each trajectory.
 - `col_which::Vector{Vector{Int}}`: The indices of which collapse operator was responsible for each quantum jump in `col_times`.
 - `converged::Bool`: Whether the solution is converged or not.
@@ -176,7 +176,7 @@ A structure storing the results and some information from solving trajectories o
 - `times::AbstractVector`: The time list of the evolution.
 - `states::Vector{Vector{QuantumObject}}`: The list of result states in each trajectory and each time point in `times`.
 - `expect::Union{AbstractArray,Nothing}`: The expectation values corresponding to each trajectory and each time point in `times`.
-- `rng::AbstractRNG`: Random number generator for reproducibility.
+- `rng::AbstractRNG`: Initial random number generator for reproducibility.
 - `measurement::Union{AbstractArray,Nothing}`: Measurements for each trajectories and stochastic collapse operators (`sc_ops`).
 - `converged::Bool`: Whether the solution is converged or not.
 - `alg`: The algorithm which is used during the solving process.