fix: handle unscalarized observed variable defaults in initialization

Author: AayushSabharwal

src/systems/nonlinear/initializesystem.jl

@@ -61,6 +61,12 @@ function generate_initializesystem_timevarying(sys::AbstractSystem;
     isempty(trueobs) || filter_delay_equations_variables!(sys, trueobs)
     vars = unique([unknowns(sys); getfield.(trueobs, :lhs)])
     vars_set = Set(vars) # for efficient in-lookup
+    arrvars = Set()
+    for var in vars
+        if iscall(var) && operation(var) === getindex
+            push!(arrvars, first(arguments(var)))
+        end
+    end
 
     eqs_ics = Equation[]
     defs = copy(defaults(sys)) # copy so we don't modify sys.defaults
@@ -74,6 +80,7 @@ function generate_initializesystem_timevarying(sys::AbstractSystem;
     if isempty(op)
         op = copy(defs)
     end
+    scalarize_vars_in_varmap!(op, arrvars)
     u0map = anydict()
     pmap = anydict()
     build_operating_point!(sys, op, u0map, pmap, Dict(), unknowns(sys),

src/systems/problem_utils.jl

@@ -523,6 +523,24 @@ function scalarize_varmap!(varmap::AbstractDict)
     return varmap
 end
 
+"""
+    $(TYPEDSIGNATURES)
+
+For each array variable in `vars`, scalarize the corresponding entry in `varmap`.
+If a scalarized entry already exists, it is not overridden.
+"""
+function scalarize_vars_in_varmap!(varmap::AbstractDict, vars)
+    for var in vars
+        symbolic_type(var) == ArraySymbolic() || continue
+        is_sized_array_symbolic(var) || continue
+        haskey(varmap, var) || continue
+        for i in eachindex(var)
+            haskey(varmap, var[i]) && continue
+            varmap[var[i]] = varmap[var][i]
+        end
+    end
+end
+
 function get_temporary_value(p, floatT = Float64)
     stype = symtype(unwrap(p))
     return if stype == Real