diff --git a/src/CSVWriter.hpp b/src/CSVWriter.hpp
index ad1f87c9b6005d7a00fde430d5c9e304ba3953b8..eb90d6702b636782b420ca26a0926680f8f7fd6b 100644
--- a/src/CSVWriter.hpp
+++ b/src/CSVWriter.hpp
@@ -181,9 +181,10 @@ class CSVWriter
 	 *
 	 * \param v_pos vector that contain the positional information
 	 * \param v_prp vector that contain the property information
+	 * \param offset from where to start
 	 *
 	 */
-	std::string get_csv_data(v_pos & vp, v_prp & vpr)
+	std::string get_csv_data(v_pos & vp, v_prp & vpr, size_t offset)
 	{
 		std::stringstream str;
 
@@ -195,7 +196,7 @@ class CSVWriter
 		}
 
 		// Write the data
-		for (size_t i = 0 ; i < vp.size() ; i++)
+		for (size_t i = offset ; i < vp.size() ; i++)
 		{
 			for (size_t j = 0 ; j < v_pos::value_type::dims ; j++)
 			{
@@ -228,10 +229,11 @@ public:
 	 * \param file path where to write
 	 * \param v_pos positional vector
 	 * \param v_prp properties vector
+	 * \param offset from where to start to write
 	 *
 	 */
 
-	bool write(std::string file, v_pos & v , v_prp & prp)
+	bool write(std::string file, v_pos & v , v_prp & prp, size_t offset=0)
 	{
 		// Header for csv (colums name)
 		std::string csv_header;
@@ -242,7 +244,7 @@ public:
 		csv_header = get_csv_colums();
 
 		// For each property in the vertex type produce a point data
-		point_data = get_csv_data(v,prp);
+		point_data = get_csv_data(v,prp,offset);
 
 		// write the file
 		std::ofstream ofs(file);
diff --git a/src/GraphMLWriter_unit_tests.hpp b/src/GraphMLWriter_unit_tests.hpp
index 17922d61ca7fbfd07563f51ebb68b76b75966ea5..2f9a011f4a8e2a42e00467ad4cc7045ac508ea64 100644
--- a/src/GraphMLWriter_unit_tests.hpp
+++ b/src/GraphMLWriter_unit_tests.hpp
@@ -131,7 +131,10 @@ BOOST_AUTO_TEST_CASE( graphml_writer_use)
 	// Box
 	Box<3,float> box({0.0,0.0,0.0},{1.0,1.0,1.0});
 
-	Graph_CSR<ne_cp,ne_cp> g_csr = g_factory.construct<5,float,2,ne_cp::x,ne_cp::y,ne_cp::z>(sz,box);
+	// Boundary conditions, non periodic
+	size_t bc[] = {NON_PERIODIC,NON_PERIODIC,NON_PERIODIC};
+
+	Graph_CSR<ne_cp,ne_cp> g_csr = g_factory.construct<5,float,2,ne_cp::x,ne_cp::y,ne_cp::z>(sz,box,bc);
 
 	// Create a graph ML
 	GraphMLWriter<Graph_CSR<ne_cp,ne_cp>> gw(g_csr);