diff --git a/Math/PolyEval.hh b/Math/PolyEval.hh
index 588abd0..adbde2b 100644
--- a/Math/PolyEval.hh
+++ b/Math/PolyEval.hh
@@ -73,15 +73,6 @@ public:
     template<class P>
     void addPolynomial(const P& p, vector<T>& v) { for(auto& m: p) addMonomial(m,v); }
 
-    /// Comparison simple algorithm
-    template<class P, class Cvec>
-    void addSimple(const P& p, vector<T>& v, const Cvec& c) const {
-        if(!v.size()) v.resize(c.size());
-        assert(v.size() <= c.size());
-        size_t i = 0;
-        for(auto& y: v) y += p(c[i++]);
-    }
-
 protected:
     vector<vector<T>> Xs;                     ///< loaded coordinate vectors
     vector<PowerSeriesEval<vector<T>>> Ps;    /// Powers by variable
diff --git a/Math/PowerSeriesEval.hh b/Math/PowerSeriesEval.hh
index 7f1d83d..914d117 100644
--- a/Math/PowerSeriesEval.hh
+++ b/Math/PowerSeriesEval.hh
@@ -25,7 +25,7 @@
 template<typename Vec>
 class PowerSeriesEval {
 public:
-
+    /// return value, deduced from vector type
     typedef typename std::remove_reference<decltype(std::declval<Vec&>()[0])>::type T;
 
     /// set x^1 values
@@ -41,7 +41,7 @@ public:
         }
     }
 
-    /// multiply by x^n
+    /// multiply vector by x^n
     void mul(Vec& v0, size_t n) {
         if(!n) return;
          auto& x = pow(n);
diff --git a/Test/testPolynomial.cc b/Test/testPolynomial.cc
index 9cdda33..89ae867 100644
--- a/Test/testPolynomial.cc
+++ b/Test/testPolynomial.cc
@@ -9,6 +9,15 @@ using std::chrono::steady_clock;
 typedef Monomial_t<3> Mxyz;
 typedef Polynomial_t<3> Pxyz;
 
+/// Comparison simple algorithm
+template<class P, class T, class Cvec>
+void addSimple(const P& p, vector<T>& v, const Cvec& c) {
+    if(!v.size()) v.resize(c.size());
+    assert(v.size() <= c.size());
+    size_t i = 0;
+    for(auto& y: v) y += p(c[i++]);
+}
+
 int main(int, char**) {
 
     std::vector<double> x(3);
@@ -47,7 +56,7 @@ int main(int, char**) {
 
     auto t1 = steady_clock::now();
 
-    for(int i=0; i<ntrials; i++) PE.addSimple(p, vp2, vc);
+    for(int i=0; i<ntrials; i++) addSimple(p, vp2, vc);
 
     auto t2 = steady_clock::now();