diff --git a/lib/Function.cpp b/lib/Function.cpp
index 65a6660..a42b7c4 100644
--- a/lib/Function.cpp
+++ b/lib/Function.cpp
@@ -101,7 +101,8 @@ double DoubleFunction::operator()(void) const
 }
 
 // bind ////////////////////////////////////////////////////////////////////////
-DoubleFunction DoubleFunction::bind(const Index argIndex, const double val)
+DoubleFunction DoubleFunction::bind(const Index argIndex,
+                                    const double val) const
 {
     Index            nArg = getNArg();
     shared_ptr<DVec> buf(new DVec(nArg));
@@ -133,6 +134,26 @@ DoubleFunction DoubleFunction::bind(const Index argIndex, const double val)
     return bindFunc;
 }
 
+DoubleFunction DoubleFunction::bind(const Index argIndex,
+                                    const DVec &x) const
+{
+    Index            nArg = getNArg();
+    shared_ptr<DVec> buf(new DVec(nArg));
+    DoubleFunction   copy(*this), bindFunc;
+
+    auto func = [copy, buf, argIndex, x](const double *arg)
+    {
+        *buf = x;
+        (*buf)(argIndex) = arg[0];
+
+        return copy(*buf);
+    };
+
+    bindFunc.setFunction(func, 1);
+
+    return bindFunc;
+}
+
 // arithmetic operators ////////////////////////////////////////////////////////
 DoubleFunction DoubleFunction::operator-(void) const
 {
@@ -222,3 +243,29 @@ DSample DoubleFunctionSample::operator()(const vector<double> &arg) const
     return (*this)(arg.data());
 }
 
+// bind ////////////////////////////////////////////////////////////////////////
+DoubleFunctionSample DoubleFunctionSample::bind(const Index argIndex,
+                                                const double val) const
+{
+    DoubleFunctionSample bindFunc(size());
+
+    FOR_STAT_ARRAY(bindFunc, s)
+    {
+        bindFunc[s] = (*this)[s].bind(argIndex, val);
+    }
+
+    return bindFunc;
+}
+
+DoubleFunctionSample DoubleFunctionSample::bind(const Index argIndex,
+                                                const DVec &x) const
+{
+    DoubleFunctionSample bindFunc(size());
+
+    FOR_STAT_ARRAY(bindFunc, s)
+    {
+        bindFunc[s] = (*this)[s].bind(argIndex, x);
+    }
+
+    return bindFunc;
+}
diff --git a/lib/Function.hpp b/lib/Function.hpp
index dd1fc2f..18049f0 100644
--- a/lib/Function.hpp
+++ b/lib/Function.hpp
@@ -54,7 +54,8 @@ public:
     template <typename... Ts>
     double operator()(const double arg0, const Ts... args) const;
     // bind
-    DoubleFunction bind(const Index argIndex, const double val);
+    DoubleFunction bind(const Index argIndex, const double val) const;
+    DoubleFunction bind(const Index argIndex, const DVec &x) const;
     // arithmetic operators
     DoubleFunction   operator-(void) const;
     DoubleFunction & operator+=(const DoubleFunction &f);
@@ -170,13 +171,16 @@ public:
     DSample operator()(const std::vector<double> &arg) const;
     template <typename... Ts>
     DSample operator()(const double arg0, const Ts... args) const;
+    // bind
+    DoubleFunctionSample bind(const Index argIndex, const double val) const;
+    DoubleFunctionSample bind(const Index argIndex, const DVec &x) const ;
 };
 
 template <typename... Ts>
 DSample DoubleFunctionSample::operator()(const double arg0,
                                          const Ts... args) const
 {
-    const double arg[] = {arg0, args...};
+    const double arg[] = {arg0, static_cast<double>(args)...};
     
     return (*this)(arg);
 }