Merge pull request #832 from AayushSabharwal/as/remake-fix

fix: fix `remake` for parameters dependent on observed variables

Author: ChrisRackauckas

src/remake.jl

@@ -515,6 +515,7 @@ function varmap_get(varmap, var, default = nothing)
     return default
 end
 
+anydict(d::Dict{Any, Any}) = d
 anydict(d) = Dict{Any, Any}(d)
 anydict() = Dict{Any, Any}()
 
@@ -658,8 +659,9 @@ function _updated_u0_p_symmap(prob, u0, ::Val{true}, p, ::Val{false}, t0)
     isdep = any(symbolic_type(v) !== NotSymbolic() for (_, v) in u0)
     isdep || return remake_buffer(prob, state_values(prob), keys(u0), values(u0)), p
 
-    u0 = anydict(k => symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, u0)
-    for (k, v) in u0)
+    for (k, v) in u0
+        u0[k] = symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, u0)
+    end
 
     isdep = any(symbolic_type(v) !== NotSymbolic() for (_, v) in u0)
     isdep || return remake_buffer(prob, state_values(prob), keys(u0), values(u0)), p
@@ -668,17 +670,19 @@ function _updated_u0_p_symmap(prob, u0, ::Val{true}, p, ::Val{false}, t0)
     # This is sort of an implicit dependency on MTK. The values of `u` won't actually be
     # used, since any state symbols in the expression were substituted out earlier.
     temp_state = ProblemState(; u = state_values(prob), p = p, t = t0)
-    u0 = anydict(k => symbolic_type(v) === NotSymbolic() ? v : getu(prob, v)(temp_state)
-    for (k, v) in u0)
+    for (k, v) in u0
+        u0[k] = symbolic_type(v) === NotSymbolic() ? v : getu(prob, v)(temp_state)
+    end
     return remake_buffer(prob, state_values(prob), keys(u0), values(u0)), p
 end
 
 function _updated_u0_p_symmap(prob, u0, ::Val{false}, p, ::Val{true}, t0)
     isdep = any(symbolic_type(v) !== NotSymbolic() for (_, v) in p)
     isdep || return u0, remake_buffer(prob, parameter_values(prob), keys(p), values(p))
 
-    p = anydict(k => symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, p)
-    for (k, v) in p)
+    for (k, v) in p
+        p[k] = symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, p)
+    end
 
     isdep = any(symbolic_type(v) !== NotSymbolic() for (_, v) in p)
     isdep || return u0, remake_buffer(prob, parameter_values(prob), keys(p), values(p))
@@ -687,8 +691,9 @@ function _updated_u0_p_symmap(prob, u0, ::Val{false}, p, ::Val{true}, t0)
     # this is sort of an implicit dependency on MTK. The values of `p` won't actually be
     # used, since any parameter symbols in the expression were substituted out earlier.
     temp_state = ProblemState(; u = u0, p = parameter_values(prob), t = t0)
-    p = anydict(k => symbolic_type(v) === NotSymbolic() ? v : getu(prob, v)(temp_state)
-    for (k, v) in p)
+    for (k, v) in p
+        p[k] = symbolic_type(v) === NotSymbolic() ? v : getu(prob, v)(temp_state)
+    end
     return u0, remake_buffer(prob, parameter_values(prob), keys(p), values(p))
 end
 
@@ -700,20 +705,14 @@ function _updated_u0_p_symmap(prob, u0, ::Val{true}, p, ::Val{true}, t0)
         return remake_buffer(prob, state_values(prob), keys(u0), values(u0)),
         remake_buffer(prob, parameter_values(prob), keys(p), values(p))
     end
-    if !isu0dep
-        u0 = remake_buffer(prob, state_values(prob), keys(u0), values(u0))
-        return _updated_u0_p_symmap(prob, u0, Val(false), p, Val(true), t0)
-    end
-    if !ispdep
-        p = remake_buffer(prob, parameter_values(prob), keys(p), values(p))
-        return _updated_u0_p_symmap(prob, u0, Val(true), p, Val(false), t0)
-    end
 
     varmap = merge(u0, p)
-    u0 = anydict(k => symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, varmap)
-    for (k, v) in u0)
-    p = anydict(k => symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, varmap)
-    for (k, v) in p)
+    for (k, v) in u0
+        u0[k] = symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, varmap)
+    end
+    for (k, v) in p
+        p[k] = symbolic_type(v) === NotSymbolic() ? v : symbolic_evaluate(v, varmap)
+    end
     return remake_buffer(prob, state_values(prob), keys(u0), values(u0)),
     remake_buffer(prob, parameter_values(prob), keys(p), values(p))
 end

test/downstream/modelingtoolkit_remake.jl

@@ -219,3 +219,13 @@ end
     @test newoprob.ps[k] == [2.0, 3.0, 4.0, 5.0]
     @test newoprob[V] == [1.5, 2.5]
 end
+
+@testset "remake with parameter dependent on observed" begin
+    @variables x(t) y(t)
+    @parameters p = x + y
+    @mtkbuild sys = ODESystem([D(x) ~ x, p ~ x + y], t)
+    prob = ODEProblem(sys, [x => 1.0, y => 2.0], (0.0, 1.0))
+    @test prob.ps[p] ≈ 3.0
+    prob2 = remake(prob; u0 = [y => 3.0], p = Dict())
+    @test prob2.ps[p] ≈ 4.0
+end