fix tests

x3042 · Feb 16, 2024 · 311f5fb · 311f5fb
1 parent 632a93e
commit 311f5fb
Showing 1 changed file with 7 additions and 4 deletions.
diff --git a/src/Reduction.jl b/src/Reduction.jl
@@ -38,12 +38,15 @@ struct Reduction{A, B, C}
     new_system::ODE{A}
     new_vars::Dict{A, B}
     old_system::ODE{C}
-    lumping_matrix::Matrix{Any}
+    lumping_matrix::Union{Nothing, Matrix{Any}}
 
     function Reduction{A, B, C}(new_system::ODE{A}, new_vars::Dict{A, B}, old_system::ODE{C}) where {A, B, C}
-        lumping_vars = [new_vars[x] for x in gens(parent(new_system))]
-        lumping_combs = [sum(collect(coefficients(comb)) .* exponent_vectors(comb)) for comb in lumping_vars]
-        lumping_matrix = mapreduce(permutedims, vcat, lumping_combs)
+        lumping_matrix = nothing
+        if !isempty(new_vars)
+            lumping_vars = [new_vars[x] for x in gens(parent(new_system))]
+            lumping_combs = [sum(collect(coefficients(comb)) .* exponent_vectors(comb)) for comb in lumping_vars]
+            lumping_matrix = mapreduce(permutedims, vcat, lumping_combs)
+        end
         return new{A, B, C}(new_system, new_vars, old_system, lumping_matrix)
     end