diff --git a/la_traits.h b/la_traits.h
index 054f4e3..788db4e 100644
--- a/la_traits.h
+++ b/la_traits.h
@@ -296,7 +296,7 @@ static void multiput(size_t n, int fd, const std::complex<C> *x, bool dimensions
 	  }
 	while(total < n);
 	}
-static void copy(std::complex<C> *dest, std::complex<C> *src, size_t n) {memcpy(dest,src,n*sizeof(std::complex<C>));}
+static void copy(std::complex<C> *dest, const std::complex<C> *src, size_t n) {memcpy(dest,src,n*sizeof(std::complex<C>));}
 static void clear(std::complex<C> *dest, size_t n) {memset(dest,0,n*sizeof(std::complex<C>));}
 static void copyonwrite(std::complex<C> &x) {};
 static bool is_plaindata() {return true;}
@@ -356,7 +356,7 @@ static void multiput(size_t n, int fd, const C *x, bool dimensions=0)
 	  }
 	while(total < n);
 	}
-static void copy(C *dest, C *src, size_t n) {memcpy(dest,src,n*sizeof(C));}
+static void copy(C *dest, const C *src, size_t n) {memcpy(dest,src,n*sizeof(C));}
 static void clear(C *dest, size_t n) {memset(dest,0,n*sizeof(C));}
 static void copyonwrite(C &x) {};
 static bool is_plaindata() {return true;}
@@ -396,7 +396,7 @@ static void put(int fd, const X<C> &x, bool dimensions=1, bool transp=0, bool or
 static void get(int fd, X<C> &x, bool dimensions=1, bool transp=0, bool orcaformat=false) {x.get(fd,dimensions,transp,orcaformat);} \
 static void multiput(size_t n,int fd, const X<C> *x, bool dimensions=1, bool orcaformat=false) {for(size_t i=0; i<n; ++i) x[i].put(fd,dimensions,false,orcaformat);} \
 static void multiget(size_t n,int fd, X<C> *x, bool dimensions=1, bool orcaformat=false) {for(size_t i=0; i<n; ++i) x[i].get(fd,dimensions,false,orcaformat);} \
-static void copy(X<C> *dest, X<C> *src, size_t n) {for(size_t i=0; i<n; ++i) dest[i]=src[i];} \
+static void copy(X<C> *dest, const X<C> *src, size_t n) {for(size_t i=0; i<n; ++i) dest[i]=src[i];} \
 static void clear(X<C> *dest, size_t n) {for(size_t i=0; i<n; ++i) dest[i].clear();}\
 static void copyonwrite(X<C> &x) {x.copyonwrite();}\
 static bool is_plaindata() {return false;}\
@@ -439,7 +439,7 @@ static void put(int fd, const X<C> &x, bool dimensions=1, bool transp=0, bool or
 static void get(int fd, X<C> &x, bool dimensions=1, bool transp=0, bool orcaformat=false) {x.get(fd,dimensions,false,orcaformat);}  \
 static void multiput(size_t n,int fd, const X<C> *x, bool dimensions=1, bool orcaformat=false) {for(size_t i=0; i<n; ++i) x[i].put(fd,dimensions,false,orcaformat);}  \
 static void multiget(size_t n,int fd, X<C> *x, bool dimensions=1, bool orcaformat=false) {for(size_t i=0; i<n; ++i) x[i].get(fd,dimensions,false,orcaformat);}  \
-static void copy(C *dest, C *src, size_t n) {for(size_t i=0; i<n; ++i) dest[i]=src[i];}  \
+static void copy(C *dest, const C *src, size_t n) {for(size_t i=0; i<n; ++i) dest[i]=src[i];}  \
 static void clear(C *dest, size_t n) {for(size_t i=0; i<n; ++i) dest[i].clear();} \
 static void copyonwrite(X<C> &x) {x.copyonwrite();} \
 static bool is_plaindata() {return false;}\
diff --git a/mat.cc b/mat.cc
index df373e9..8d9c701 100644
--- a/mat.cc
+++ b/mat.cc
@@ -113,6 +113,29 @@ const NRVec<T> NRMat<T>::row(const int i, int l) const {
 	return r;
 }
 
+
+/***************************************************************************//**
+ * store given row of this matrix of general type <code>T</code>
+ * @param[in] i row index starting from zero
+ * @param[in] l consider this value as the count of columns
+ ******************************************************************************/
+template <typename T>
+void NRMat<T>::rowset(const NRVec<T> &r, const int i, int l) {
+#ifdef DEBUG
+	if(i < 0 || i >= nn) laerror("illegal index");
+#endif
+	if(l < 0) l = mm;
+	LA_traits<T>::copy(
+#ifdef MATPTR
+	        v[i]
+#else
+		v + i*(size_t)l
+#endif
+		, &r[0], l);
+}
+
+
+
 /***************************************************************************//**
  * routine for raw output
  * @param[in] fd file descriptor for output
diff --git a/mat.h b/mat.h
index eba5a8e..c12d61a 100644
--- a/mat.h
+++ b/mat.h
@@ -266,6 +266,9 @@ public:
 	//! get the i<sup>th</sup> row
 	const NRVec<T> row(const int i, int l = -1) const;
 
+	//! set the i<sup>th</sup> row
+	void rowset(const NRVec<T> &r, const int i, int l = -1);
+
 	//! get the j<sup>th</sup> column
 	const NRVec<T> column(const int j, int l = -1) const {
 		NOT_GPU(*this);
@@ -275,6 +278,13 @@ public:
 		return r;
 	};
 
+	//! set the j<sup>th</sup> column
+	void columnset(const NRVec<T> &r, const int j, int l = -1) {
+		NOT_GPU(*this);
+		if(l < 0) l = nn;
+		for(register int i=0; i<l; ++i) (*this)(i,j) = r[i];
+	};
+
 	//! extract the digonal elements of this matrix and store them into a vector
 	const T* diagonalof(NRVec<T> &, const bool divide = 0, bool cache = false) const;
 	//! set diagonal elements