Handle complex eigval in critical point measure

Author: moyner

src/utils.jl

@@ -147,7 +147,11 @@ function michelsen_critical_point_measure!(S, eos, p, T, mole_numbers)
             B[i, j] = (i == j) + sqrt(n_i*n_j)*(f_i.partials[j])
         end
     end
-    return minimum(eigvals!(B))
+    v = Inf
+    for x in eigvals!(B)
+        v = min(v, real(x))
+    end
+    return v
 end
 
 function mole_fraction_from_mole_numbers_with_ad!(z::AbstractVector{ForwardDiff.Dual{T, V, N}}, mole_numbers) where {T, V, N}