fix: fix initialization with dummy derivatives of multidimensional arrays

Author: AayushSabharwal

src/systems/diffeqs/abstractodesystem.jl

@@ -857,6 +857,7 @@ function process_DEProblem(constructor, sys::AbstractODESystem, u0map, parammap;
     varmap = u0map === nothing || isempty(u0map) || eltype(u0map) <: Number ?
              defaults(sys) :
              merge(defaults(sys), todict(u0map))
+    varmap = canonicalize_varmap(varmap)
     varlist = collect(map(unwrap, dvs))
     missingvars = setdiff(varlist, collect(keys(varmap)))
 

src/variables.jl

@@ -216,6 +216,7 @@ function canonicalize_varmap(varmap; toterm = Symbolics.diff2term)
         if Symbolics.isarraysymbolic(k) && Symbolics.shape(k) !== Symbolics.Unknown()
             for i in eachindex(k)
                 new_varmap[k[i]] = v[i]
+                new_varmap[toterm(k[i])] = v[i]
             end
         end
     end

test/initial_values.jl

@@ -67,3 +67,10 @@ varmap = Dict(p => ones(3), q => 2ones(3))
 cvarmap = ModelingToolkit.canonicalize_varmap(varmap)
 target_varmap = Dict(p => ones(3), q => 2ones(3), q[1] => 2.0, q[2] => 2.0, q[3] => 2.0)
 @test cvarmap == target_varmap
+
+# Initialization of ODEProblem with dummy derivatives of multidimensional arrays
+# Issue#1283
+@variables z(t)[1:2, 1:2]
+eqs = [D(D(z)) ~ ones(2, 2)]
+@mtkbuild sys = ODESystem(eqs, t)
+@test_nowarn ODEProblem(sys, [z => zeros(2, 2), D(z) => ones(2, 2)], (0.0, 10.0))