refactor: remove denominators in generate_function and calculate_jacobian

Author: AayushSabharwal

src/systems/diffeqs/abstractodesystem.jl

@@ -82,8 +82,14 @@ function calculate_jacobian(sys::AbstractODESystem;
                 jac[i, j] = 0
             end
         end
+
+        (Is, Js, Vs) = findnz(jac)
+        for (i, j) in zip(Is, Js)
+            jac[i, j] = remove_denominators(jac[i, j])
+        end
     else
         jac = jacobian(rhs, dvs, simplify = simplify)
+        jac = remove_denominators.(jac)
     end
 
     if isequal(dvs, unknowns(sys))
@@ -198,12 +204,17 @@ function generate_function(sys::AbstractODESystem, dvs = unknowns(sys),
                nothing,
         isdde = false,
         kwargs...)
-    eqs = [eq for eq in equations(sys)]
-    if !implicit_dae
+    eqs = full_equations(sys)
+    if implicit_dae
+        rhss = [_iszero(eq.lhs) ? eq.rhs : eq.rhs - eq.lhs for eq in eqs]
+        rhss = remove_denominators.(rhss)
+    else
         check_operator_variables(eqs, Differential)
         check_lhs(eqs, Differential, Set(dvs))
+        alge_idxs = is_alg_equation.(eqs)
+        rhss = [eq.rhs for eq in eqs]
+        rhss[alge_idxs] .= remove_denominators.(rhss[alge_idxs])
     end
-
     rhss = implicit_dae ? [_iszero(eq.lhs) ? eq.rhs : eq.rhs - eq.lhs for eq in eqs] :
            [eq.rhs for eq in eqs]