diff --git a/src/Debug/debug.hpp b/src/Debug/debug.hpp
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+++ b/src/Debug/debug.hpp
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+/*
+ * debug.hpp
+ *
+ *  Created on: Oct 17, 2018
+ *      Author: i-bird
+ */
+
+#ifndef DEBUG_HPP_
+#define DEBUG_HPP_
+
+enum debug_run
+{
+	HOST,
+	DEVICE
+};
+
+enum debug_iterator
+{
+	DOMAIN_IT,
+	DOMAIN_GHOST_IT,
+	GHOST_IT,
+};
+
+
+
+/*! \brief Find in a vector dist particles if "certain conditions"
+ *
+ * This function in in general used to debug. Many time in order to discover problem we want to control if particles/grid points has zeros or out of range values.
+ * You can implement these check, by creating the loops manually or using the function debug_find with a lambda function.
+ *
+ *
+ * @param vd distributed vector
+ * @param fun_test function that define the test
+ * @param fun_print function to print a message
+ * @param it iterator type domain, domain + ghost, ghost
+ * @param type_of_run optionally can do the scan on device
+ *
+ * /return This function return true if the debug function has been triggered
+ *
+ */
+template<typename vector_dist_type, typename functor_test, typename functor_print>
+bool debug_find(vector_dist_type vd, functor_test fun_test, functor_print fun_print,
+		        debug_iterator it = debug_iterator::DOMAIN_IT, debug_run type_of_run = debug_run::HOST,
+		        bool print = true)
+{
+	vector_dist_iterator ite(0,0);
+
+	if (it == debug_iterator::DOMAIN_IT)
+	{ite = vd.getDomainIterator();}
+	else if (it == debug_iterator::DOMAIN_GHOST_IT)
+	{ite = vd.getDomainAndGhostIterator();}
+	else
+	{ite = vd.getGhostIterator();}
+
+	bool test_tot = false;
+
+	while (ite.isNext())
+	{
+		bool test = fun_test(ite.get().getKey());
+		test_tot |= test;
+
+		if (test == true && print == true)
+		{std::cout << fun_print(ite.get().getKey()) << std::endl;}
+
+		++ite;
+	}
+
+	return test_tot;
+}
+
+/*! \brief Find in a vector dist particles if "certain conditions"
+ *
+ * This function in in general used to debug. Many time in order to discover problem we want to control if particles/grid points has zeros or out of range values.
+ * You can implement these check, by creating the loops manually or using the function debug_find with a lambda function.
+ *
+ *
+ * @param vd distributed vector
+ * @param fun_test function that define the test
+ * @param fun_print function to print a message
+ * @param it iterator type domain, domain + ghost, ghost
+ * @param type_of_run optionally can do the scan on device
+ *
+ * /return This function return true if the debug function has been triggered
+ *
+ */
+template<typename vector_type, typename functor_test, typename functor_print>
+bool debug_find_single(vector_type vd, functor_test fun_test, functor_print fun_print,
+		        size_t g_m, debug_iterator it = debug_iterator::DOMAIN_IT, debug_run type_of_run = debug_run::HOST,
+		        bool print = true)
+{
+	openfpm::vector_key_iterator ite(0,0);
+
+	if (it == debug_iterator::DOMAIN_IT)
+	{ite = vd.getIteratorTo(g_m);}
+	else if (it == debug_iterator::DOMAIN_GHOST_IT)
+	{ite = vd.getIterator();}
+	else
+	{ite = vd.getIteratorFrom(g_m);}
+
+	bool test_tot = false;
+
+	while (ite.isNext())
+	{
+		bool test = fun_test(ite.get());
+		test_tot |= test;
+
+		if (test == true && print == true)
+		{std::cout << fun_print(ite.get()) << std::endl;}
+
+		++ite;
+	}
+
+	return test_tot;
+}
+
+/*! \brief scan for a particle inside a box
+ *
+ *
+ * \param vd vector_dist
+ * \param box box
+ * \param it iterator type
+ * \param type_of_run check host or device memory
+ * \return true if one or more is detected
+ */
+template<typename vector_dist_type>
+bool debug_is_in_box(vector_dist_type & vd, Box<vector_dist_type::dims, typename vector_dist_type::stype> box,
+		             debug_iterator it = debug_iterator::DOMAIN_IT, debug_run type_of_run = debug_run::HOST,
+		             bool print = true)
+{
+	auto fun_test = [&vd,&box](unsigned int p){return box.isInside(vd.getPos(p));};
+	auto fun_print = [&vd,&box](unsigned int p)
+					 {
+						std::stringstream message;
+						message << "Debug info: detected particle p=" << p << " inside box: " << box.toString() << std::endl;
+						return message.str();
+					 };
+
+	return debug_find(vd,fun_test,fun_print,it,type_of_run,print);
+}
+
+
+/*! \brief scan for a particle inside a box
+ *
+ *
+ * \param vd vector_dist
+ * \param box box
+ * \param it iterator type
+ * \param type_of_run check host or device memory
+ * \return true if one or more is detected
+ */
+template<typename vector_type>
+bool debug_is_in_box_single(vector_type & vd, Box<vector_type::value_type::dims, typename vector_type::value_type::coord_type> box,
+		             size_t g_m, std::string message = std::string() , debug_iterator it = debug_iterator::DOMAIN_IT, debug_run type_of_run = debug_run::HOST,
+		             bool print = true)
+{
+	auto fun_test = [&vd,&box](unsigned int p){return box.isInside(vd.template get<0>(p));};
+	auto fun_print = [&vd,&box,&message](unsigned int p)
+					 {
+						std::stringstream message_srm;
+						message_srm << "Debug info: " << message << " detected particle p=" << p << " inside box: " << box.toString() << std::endl;
+						return message_srm.str();
+					 };
+
+	return debug_find_single(vd,fun_test,fun_print,g_m,it,type_of_run,print);
+}
+
+#endif /* DEBUG_HPP_ */