Index: src/jacobian.cpp
===================================================================
--- src/jacobian.cpp	(revision 29864)
+++ src/jacobian.cpp	(working copy)
@@ -53,6 +53,14 @@
         delete [] twists;
     }

+    void Jacobian::resize(unsigned int newSize, unsigned int newNr)
+    {
+      delete [] twists;
+      twists = new Twist[newSize*newNr];
+      size = newSize;
+      nr_blocks = newNr;
+    }
+
     double Jacobian::operator()(int i,int j)const
     {
         assert(i<6*nr_blocks&&j<size);
Index: src/jntarrayacc.hpp
===================================================================
--- src/jntarrayacc.hpp	(revision 29864)
+++ src/jntarrayacc.hpp	(working copy)
@@ -36,11 +36,13 @@
         JntArray qdot;
         JntArray qdotdot;
     public:
-        JntArrayAcc(unsigned int size);
+        JntArrayAcc(unsigned int size=0);
         JntArrayAcc(const JntArray& q,const JntArray& qdot,const JntArray& qdotdot);
         JntArrayAcc(const JntArray& q,const JntArray& qdot);
         JntArrayAcc(const JntArray& q);

+        void resize(unsigned int newSize);
+
         JntArray value()const;
         JntArray deriv()const;
         JntArray dderiv()const;
Index: src/jntarrayvel.hpp
===================================================================
--- src/jntarrayvel.hpp	(revision 29864)
+++ src/jntarrayvel.hpp	(working copy)
@@ -35,10 +35,12 @@
         JntArray q;
         JntArray qdot;
     public:
-        JntArrayVel(unsigned int size);
+        JntArrayVel(unsigned int size=0);
         JntArrayVel(const JntArray& q,const JntArray& qdot);
         JntArrayVel(const JntArray& q);

+        void resize(unsigned int newSize);
+
         JntArray value()const;
         JntArray deriv()const;

Index: src/jntarrayacc.cpp
===================================================================
--- src/jntarrayacc.cpp	(revision 29864)
+++ src/jntarrayacc.cpp	(working copy)
@@ -42,6 +42,13 @@
     {
     }

+    void JntArrayAcc::resize(unsigned int newSize)
+    {
+      q.resize(newSize);
+      qdot.resize(newSize);
+      qdotdot.resize(newSize);
+    }
+
     JntArray JntArrayAcc::value()const
     {
         return q;
Index: src/jacobian.hpp
===================================================================
--- src/jacobian.hpp	(revision 29864)
+++ src/jacobian.hpp	(working copy)
@@ -37,9 +37,11 @@
         unsigned int nr_blocks;
     public:
         Twist* twists;
-        Jacobian(unsigned int size,unsigned int nr=1);
+        Jacobian(unsigned int size=0,unsigned int nr=1);
         Jacobian(const Jacobian& arg);

+        void resize(unsigned int newSize, unsigned int newNnr);
+
         Jacobian& operator=(const Jacobian& arg);

         bool operator ==(const Jacobian& arg);
Index: src/jntarrayvel.cpp
===================================================================
--- src/jntarrayvel.cpp	(revision 29864)
+++ src/jntarrayvel.cpp	(working copy)
@@ -38,6 +38,12 @@
     {
     }

+    void JntArrayVel::resize(unsigned int newSize)
+    {
+      q.resize(newSize);
+      qdot.resize(newSize);
+    }
+
     JntArray JntArrayVel::value()const
     {
         return q;