add solution interfacing

src/Catalyst.jl

@@ -171,14 +171,16 @@ include("spatial_reaction_systems/spatial_reactions.jl")
 export TransportReaction, TransportReactions, @transport_reaction
 export isedgeparameter
 
-# Lattice reaction systems
+# Lattice reaction systems.
 include("spatial_reaction_systems/lattice_reaction_systems.jl")
 export LatticeReactionSystem
 export spatial_species, vertex_parameters, edge_parameters
 export CartesianGrid, CartesianGridReJ # (Implemented in JumpProcesses)
 export has_cartesian_lattice, has_masked_lattice, has_grid_lattice, has_graph_lattice,
        grid_dims, grid_size
 export make_edge_p_values, make_directed_edge_values
+include("spatial_reaction_systems/lattice_solution_interfacing.jl")
+export get_lrs_vals
 
 # Specific spatial problem types.
 include("spatial_reaction_systems/spatial_ODE_systems.jl")

src/spatial_reaction_systems/lattice_jump_systems.jl

@@ -122,7 +122,8 @@ end
 
 ### Extra ###
 
-# Temporary. Awaiting implementation in SII, or proper implementation withinCatalyst (with more general functionality).
+# Temporary. Awaiting implementation in SII, or proper implementation within Catalyst (with 
+# more general functionality).
 function int_map(map_in, sys)
     return [ModelingToolkit.variable_index(sys, pair[1]) => pair[2] for pair in map_in]
 end
@@ -141,3 +142,14 @@ end
 #     majpmapper = ModelingToolkit.JumpSysMajParamMapper(js, p; jseqs = eqs, rateconsttype = invttype)
 #     return ModelingToolkit.assemble_maj(eqs.x[1], statetoid, majpmapper)
 # end
+
+
+### Problem & Integrator Rebuilding ###
+
+# Currently not implemented.
+function rebuild_lat_internals!(dprob::DiscreteProblem)
+    error("Modification and/or rebuilding of `DiscreteProblem`s is currently not supported. Please create a new problem instead.")
+end
+function rebuild_lat_internals!(jprob::JumpProblem)
+    error("Modification and/or rebuilding of `JumpProblem`s is currently not supported. Please create a new problem instead.")
+end

src/spatial_reaction_systems/lattice_solution_interfacing.jl

@@ -0,0 +1,121 @@
+### Rudimentary Interfacing Function ###
+# A single function, `get_lrs_vals`, which contain all interfacing functionality. However, 
+# long-term it should be replaced with a sleeker interface. Ideally as MTK-wider support for 
+# lattice problems and solutions are introduced. 
+
+"""
+    get_lrs_vals(sol, sp, lrs::LatticeReactionSystem; t = nothing)
+
+A function for retrieving the solution of a `LatticeReactionSystem`-based simulation on various
+desired forms. Generally, for `LatticeReactionSystem`s, the values in `sol` is ordered in a 
+way which is not directly interpretable by the user. Furthermore, the normal Catalyst interface
+for solutions (e.g. `sol[:X]`) does not work for these solutions. Hence this function is used instead.
+
+The output is a vector, which in each position contain sp's value (either at a time step of time,
+depending on the input `t`). Its shape depends on the lattice (using a similar form as heterogeneous
+initial conditions). I.e. for a NxM cartesian grid, the values are NxM matrices. For a masked grid,
+the values are sparse matrices. For a graph lattice, the values are vectors (where the value in
+the n'th position corresponds to sp's value in the n'th vertex).
+
+Arguments:
+- `sol`: The solution from which we wish to retrieve some values.
+- `sp`: The species which values we wish to retrieve. Can be either a symbol (e.g. `:X`) or a symbolic
+variable (e.g. `X`).
+- `lrs`: The `LatticeReactionSystem` which was simulated to generate the solution.
+- `t = nothing`: If `nothing`, we simply returns the solution across all saved timesteps. If `t`
+instead is a vector (or range of values), returns the solutions interpolated at these timepoints.
+
+Notes:
+- The `get_lrs_vals` is not optimised for performance. However, it should still be quite performant,
+but there might be some limitations if called a very large number of times.
+- Long-term it is likely that this function gets replaced with a sleeker interface.
+
+Example:
+```julia
+using Catalyst, OrdinaryDiffEq
+
+# Prepare `LatticeReactionSystem`s.
+rs = @reaction_network begin
+    (k1,k2), X1 <--> X2
+end
+tr = @transport_reaction D X1 
+lrs = LatticeReactionSystem(rs, [tr], CartesianGrid((2,2)))
+
+# Create problems.
+u0 = [:X1 => 1, :X2 => 2]
+tspan = (0.0, 10.0)
+ps = [:k1 => 1, :k2 => 2.0, :D => 0.1]
+
+oprob = ODEProblem(lrs1, u0, tspan, ps)
+osol = solve(oprob1, Tsit5())
+get_lrs_vals(osol, :X1, lrs) # Returns the value of X1 at each timestep.
+get_lrs_vals(osol, :X1, lrs; t = 0.0:10.0) # Returns the value of X1 at times 0.0, 1.0, ..., 10.0
+```
+"""
+function get_lrs_vals(sol, sp, lrs::LatticeReactionSystem; t = nothing)
+    # Figures out which species we wish to fetch information about.
+    (sp isa Symbol) && (sp = Catalyst._symbol_to_var(lrs, sp))
+    sp_idx = findfirst(isequal(sp), species(lrs))
+    sp_tot = length(species(lrs))
+
+    # Extracts the lattice and calls the next function. Masked grids (Array of Bools) are converted
+    # to sparse array using the same template size as we wish to shape the data to.
+    lattice = Catalyst.lattice(lrs)
+    if has_masked_lattice(lrs) 
+        if grid_dims(lrs) == 3
+            error("The `get_lrs_vals` function is not defined for systems based on 3d sparse arrays. Please raise an issue at the Catalyst GitHub site if this is something which would be useful to you.")
+        end
+        lattice = sparse(lattice)
+    end
+    get_lrs_vals(sol, lattice, t, sp_idx, sp_tot)
+end
+
+# Function which handles the input in the case where `t` is `nothing` (i.e. return `sp`s value
+# across all sample points).
+function get_lrs_vals(sol, lattice, t::Nothing, sp_idx, sp_tot)
+    # ODE simulations contain, in each data point, all values in a single vector. Jump simulations
+    # instead in a matrix (NxM, where N is the number of species and M the number of vertices). We
+    # must consider each case separately.
+    if sol.prob isa ODEProblem
+        return [reshape_vals(vals[sp_idx:sp_tot:end], lattice) for vals in sol.u]
+    elseif sol.prob isa DiscreteProblem
+        return [reshape_vals(vals[sp_idx,:], lattice) for vals in sol.u]
+    else
+        error("Unknown type of solution provided to `get_lrs_vals`. Only ODE or Jump solutions are supported.")
+    end
+end
+
+# Function which handles the input in the case where `t` is a range of values (i.e. return `sp`s 
+# value at all designated time points.
+function get_lrs_vals(sol, lattice, t::AbstractVector{T}, sp_idx, sp_tot) where {T <: Number}
+    if (minimum(t) < sol.t[1]) || (maximum(t) > sol.t[end])
+        error("The range of the t values provided for sampling, ($(minimum(t)),$(maximum(t))) is not fully within the range of the simulation time span ($(sol.t[1]),$(sol.t[end])).")
+    end
+
+    # ODE simulations contain, in each data point, all values in a single vector. Jump simulations
+    # instead in a matrix (NxM, where N is the number of species and M the number of vertices). We
+    # must consider each case separately.
+    if sol.prob isa ODEProblem
+        return [reshape_vals(sol(ti)[sp_idx:sp_tot:end], lattice) for ti in t]
+    elseif sol.prob isa DiscreteProblem
+        return [reshape_vals(sol(ti)[sp_idx,:], lattice) for ti in t]
+    else
+        error("Unknown type of solution provided to `get_lrs_vals`. Only ODE or Jump solutions are supported.")
+    end
+end
+
+# Functions which in each sample point reshapes the vector of values to the correct form (depending
+# on the type of lattice used).
+function reshape_vals(vals, lattice::CartesianGridRej{N, T}) where {N,T}
+    return reshape(vals, lattice.dims...)
+end
+function reshape_vals(vals, lattice::AbstractSparseArray{Bool, Int64, 1})
+    return SparseVector(lattice.n, lattice.nzind, vals)
+end
+function reshape_vals(vals, lattice::AbstractSparseArray{Bool, Int64, 2})
+    return SparseMatrixCSC(lattice.m, lattice.n, lattice.colptr, lattice.rowval, vals)
+end
+function reshape_vals(vals, lattice::DiGraph)
+    return vals
+end
+

src/spatial_reaction_systems/spatial_ODE_systems.jl

@@ -243,10 +243,10 @@ function build_odefunction(lrs::LatticeReactionSystem, vert_ps::Vector{Pair{R, V
         jac_transport, transport_rates)
     J = (jac ? f : nothing)
 
-    # Extracts the `Symbol` form for species and parameters. Creates and returns the `ODEFunction`.
-    syms = MT.getname.(species(lrs))
-    paramsyms = MT.getname.(parameters(lrs))
-    return ODEFunction(f; jac = J, jac_prototype, syms, paramsyms)
+    # Extracts the `Symbol` form for parameters (but not species). Creates and returns the `ODEFunction`.
+    paramsyms = [MT.getname(p) for p in parameters(lrs)]
+    sys = SciMLBase.SymbolCache([], paramsyms, [])
+    return ODEFunction(f; jac = J, jac_prototype, sys)
 end
 
 # Builds a jacobian prototype.
@@ -325,7 +325,48 @@ end
 
 ### Functor Updating Functionality ###
 
-# Function for rebuilding a `LatticeReactionSystem` `ODEProblem` after it has been updated.
+"""
+    rebuild_lat_internals!(sciml_struct)
+
+Rebuilds the internal functions for simulating a LatticeReactionSystem. WHenever a problem or 
+integrator have had its parameter values updated, thus function should be called for the update to 
+be taken into account. For ODE simulations, `rebuild_lat_internals!` needs only to be called when
+- An edge parameter have been updated.
+- When a parameter with spatially homogeneous values have been given spatially heterogeneous values 
+(or vice versa).
+
+Arguments:
+- `sciml_struct`: The problem (e.g. an `ODEProblem`) or an integrator which we wish to rebuild.
+
+Notes:
+- Currently does not work for `DiscreteProblem`s, `JumpProblem`s, or their integrators.
+- The function is not build with performance in mind, so avoid calling it multiple times in 
+performance-critical applications.
+
+Example:
+```julia
+# Creates an initial `ODEProblem`
+rs = @reaction_network begin
+    (k1,k2), X1 <--> X2
+end
+tr = @transport_reaction D X1 
+grid = CartesianGrid((2,2))
+lrs = LatticeReactionSystem(rs, [tr], grid)
+
+u0 = [:X1 => 2, :X2 => [5 6; 7 8]]
+tspan = (0.0, 10.0)
+ps = [:k1 => 1.5, :k2 => [1.0 1.5; 2.0 3.5], :D => 0.1]
+
+oprob = ODEProblem(lrs, u0, tspan, ps)
+
+# Updates parameter values.
+oprob.ps[:ks] = [2.0 2.5; 3.0 4.5]
+oprob.ps[:D] = 0.05
+
+# Rebuilds `ODEProblem` to make changes have an effect.
+rebuild_lat_internals!(oprob)
+```
+"""
 function rebuild_lat_internals!(oprob::ODEProblem)
     rebuild_lat_internals!(oprob.f.f, oprob.p, oprob.f.f.lrs)
 end

test/runtests.jl

@@ -72,5 +72,6 @@ using SafeTestsets, Test
     @time @safetestset "Spatial Lattice Variants" begin include("spatial_modelling/lattice_reaction_systems_lattice_types.jl") end
     @time @safetestset "ODE Lattice Systems Simulations" begin include("spatial_modelling/lattice_reaction_systems_ODEs.jl") end
     @time @safetestset "Jump Lattice Systems Simulations" begin include("spatial_modelling/lattice_reaction_systems_jumps.jl") end
+    @time @safetestset "Jump Solution Interfacing" begin include("spatial_modelling/lattice_solution_interfacing.jl") end
 
 end # @time

test/spatial_modelling/lattice_reaction_systems_jumps.jl

@@ -1,8 +1,7 @@
 ### Preparations ###
 
 # Fetch packages.
-using JumpProcesses
-using Random, Statistics, SparseArrays, Test
+using JumpProcesses, Statistics, SparseArrays, Test
 
 # Fetch test networks.
 include("../spatial_test_networks.jl")
@@ -204,6 +203,27 @@ end
 
 ### JumpProblem & Integrator Interfacing ### 
 
+# Currently not supported, check that corresponding functions yields errors.
+let
+    # Prepare `LatticeReactionSystem`.
+    rs = @reaction_network begin
+        (k1,k2), X1 <--> X2
+    end
+    tr = @transport_reaction D X1 
+    grid = CartesianGrid((2,2))
+    lrs = LatticeReactionSystem(rs, [tr], grid)
+
+    # Create problems.
+    u0 = [:X1 => 2, :X2 => [5 6; 7 8]]
+    tspan = (0.0, 10.0)
+    ps = [:k1 => 1.5, :k2 => [1.0 1.5; 2.0 3.5], :D => 0.1]
+    dprob = DiscreteProblem(lrs, u0, tspan, ps)
+    jprob = JumpProblem(lrs, dprob, NSM())
+
+    # Checks that rebuilding errors.
+    @test_throws Exception rebuild_lat_internals!(dprob)
+    @test_throws Exception rebuild_lat_internals!(jprob)
+end
 
 ### Other Tests ###