diff --git a/COPYING b/COPYING
index 88798ab..caeca07 120000
--- a/COPYING
+++ b/COPYING
@@ -1 +1 @@
-/usr/share/automake-1.15/COPYING
\ No newline at end of file
+/usr/share/automake-1.14/COPYING
\ No newline at end of file
diff --git a/INSTALL b/INSTALL
index ddcdb76..f812f5a 120000
--- a/INSTALL
+++ b/INSTALL
@@ -1 +1 @@
-/usr/share/automake-1.15/INSTALL
\ No newline at end of file
+/usr/share/automake-1.14/INSTALL
\ No newline at end of file
diff --git a/ax_cxx_compile_stdcxx_11.m4 b/ax_cxx_compile_stdcxx_11.m4
index e3fc158..e3c8d75 100644
--- a/ax_cxx_compile_stdcxx_11.m4
+++ b/ax_cxx_compile_stdcxx_11.m4
@@ -201,15 +201,16 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX_14], [dnl
       AC_MSG_ERROR([*** A compiler with support for C++14 language features is required.])
     fi
   else
+    HAVE_CXX11=${HAVE_CXX14}
     if test x$ac_success = xno; then
       HAVE_CXX14=0
       AC_MSG_NOTICE([No compiler with C++14 support was found])
+      AX_CXX_COMPILE_STDCXX_11([$1], [optional])
     else
       HAVE_CXX14=1
       AC_DEFINE(HAVE_CXX14,1,
                 [define if the compiler supports basic C++14 syntax])
     fi
-    HAVE_CXX11=${HAVE_CXX14}
     AC_SUBST(HAVE_CXX11)
     AC_SUBST(HAVE_CXX14)
   fi
diff --git a/ax_init_standard_project.m4 b/ax_init_standard_project.m4
index 4128d9f..04f89ac 100644
--- a/ax_init_standard_project.m4
+++ b/ax_init_standard_project.m4
@@ -129,7 +129,7 @@ AC_DEFUN([AX_SUBST], [
 # m4_define(x_minor, MINOR_NUMBER) # project's minor version
 # m4_include(ax_init_standard_project.m4)
 # AC_INIT(x_package_name, x_version, x_bugreport, x_package_name)
-# AM_INIT_AUTOMAKE([1.9 tar-pax])
+# AM_INIT_AUTOMAKE([1.9 tar-pax parallel-tests color-tests])
 # AX_INIT_STANDARD_PROJECT
 #
 # you change nothing but: YOUR_PACKAGE_NAME, MAJOR_NUMBER, MINOR_NUMBER
@@ -242,6 +242,21 @@ AC_DEFUN([AX_INIT_STANDARD_PROJECT], [
   else
     AM_CPPFLAGS="${AM_CPPFLAGS} -DQT_NO_DEBUG_OUTPUT -DQT_NO_DEBUG"
   fi
+
+  AC_ARG_WITH(gcov,
+    [AS_HELP_STRING([--with-gcov=FILE],
+                    [enable gcov, set gcov file (defaults to gcov)])],
+    [GCOV="$enableval"], [GCOV="no"])
+  AM_CONDITIONAL(COVERAGE, test "$GCOV" != "no")
+  if test "$GCOV" != "no"; then
+    if test "$GCOV" == "yes"; then
+      GCOV=gcov
+    fi
+    AC_MSG_NOTICE([Coverage tests enabled, using ${GCOV}]);
+    AM_CXXFLAGS="${AM_CXXFLAGS:-} -O0 --coverage -fprofile-arcs -ftest-coverage"
+    AM_LDFLAGS="${AM_LDFLAGS} -O0 --coverage -fprofile-arcs"
+    AX_SUBST(GCOV)
+  fi
   
   if test -f ${PACKAGE_NAME}.desktop.in; then
     AC_CONFIG_FILES([${PACKAGE_NAME}.desktop])
@@ -273,7 +288,7 @@ EOF
 AC_DEFUN([AX_USE_CXX], [
   m4_include(ax_cxx_compile_stdcxx_11.m4)
   AC_LANG(C++)
-  AX_CXX_COMPILE_STDCXX_11(noext, optional)
+  AX_CXX_COMPILE_STDCXX_14(noext, optional)
   AC_PROG_CXX
   AC_PROG_CPP
 
diff --git a/bootstrap.sh b/bootstrap.sh
index 22e0c7b..35cf0b3 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -129,6 +129,7 @@ GENERATED FILES
     * ax_init_standard_project.m4 - auxiliary macro definition file
     * ax_cxx_compile_stdcxx_11.m4 - auxiliary macro definition file
     * ax_check_qt.m4 - auxiliary macro definition file
+    * makefile_test.inc.am - makefile to be included in tests
     * resolve-debbuilddeps.sh - script to install debian package dependencies
     * resolve-rpmbuilddeps.sh - script to install RPM package dependencies
     * build-in-docker.sh - script to build the project encapsulated in a docker container
@@ -500,6 +501,7 @@ copy ${MY_NAME}
 copy ax_init_standard_project.m4
 copy ax_cxx_compile_stdcxx_11.m4
 copy ax_check_qt.m4
+copy makefile_test.inc.am
 copy resolve-debbuilddeps.sh
 copy resolve-rpmbuilddeps.sh
 copy build-in-docker.sh
diff --git a/makefile_test.inc.am b/makefile_test.inc.am
new file mode 100644
index 0000000..a4e05fa
--- /dev/null
+++ b/makefile_test.inc.am
@@ -0,0 +1,5 @@
+## @id $Id$
+
+##       1         2         3         4         5         6         7         8
+## 45678901234567890123456789012345678901234567890123456789012345678901234567890
+
diff --git a/src/matrix.hxx b/src/matrix.hxx
index f6c3538..c331739 100644
--- a/src/matrix.hxx
+++ b/src/matrix.hxx
@@ -84,6 +84,41 @@ template<typename TYPE, typename ARRAY=TYPE*> class MatrixBase {
 
     ///}
 
+    /// @name element access
+    ///{
+    
+    TYPE& at(size_t row, size_t column) {
+      assert(row<ROWS);
+      assert(column<COLUMNS);
+      return *((TYPE*)_c+row*COLUMNS+column);
+    }
+    
+    const TYPE& at(size_t row, size_t column) const {
+      assert(row<ROWS);
+      assert(column<COLUMNS);
+      return *((TYPE*)_c+row*COLUMNS+column);
+    }
+    
+    TYPE& operator()(size_t row, size_t column) {
+      return at(row, column);
+    }
+    
+    const TYPE& operator()(size_t row, size_t column) const {
+      return at(row, column);
+    }
+    
+    RowVector operator[](size_t row) {
+      assert(row<ROWS);
+      return RowVector(*this, (TYPE*)_c+row*COLUMNS);
+    }
+    
+    const ConstRowVector operator[](size_t row) const {
+      assert(row<ROWS);
+      return ConstRowVector(*this, (TYPE*)_c+row*COLUMNS);
+    }
+    
+    ///}
+
     /// @name operators
     ///{
     
@@ -138,33 +173,32 @@ template<typename TYPE, typename ARRAY=TYPE*> class MatrixBase {
 
     ///}
 
-    /// @name element access
+    /// @name special operations
     ///{
-    
-    TYPE& operator()(size_t row, size_t column) {
-      assert(row<ROWS);
-      assert(column<COLUMNS);
-      return *((TYPE*)_c+row*COLUMNS+column);
-    }
-    
-    const TYPE& operator()(size_t row, size_t column) const {
-      assert(row<ROWS);
-      assert(column<COLUMNS);
-      return *((TYPE*)_c+row*COLUMNS+column);
-    }
-    
-    RowVector operator[](size_t row) {
-      assert(row<ROWS);
-      return RowVector(*this, (TYPE*)_c+row*COLUMNS);
-    }
-    
-    const ConstRowVector operator[](size_t row) const {
-      assert(row<ROWS);
-      return ConstRowVector(*this, (TYPE*)_c+row*COLUMNS);
+
+    TYPE det() {
+      // rule of sarrus
+      TYPE res(0);
+      assert(ROWS==COLUMNS); // not really necessary
+      // 1) terms to add
+      for (size_t i(0); i<COLUMNS; ++i) {
+        TYPE term(1);
+        for (size_t j(0); j<ROWS; ++j)
+          term *= at((i+j)%COLUMNS, j);
+        res += term;
+      }
+      // 2) terms to subtract
+      for (size_t i(0); i<COLUMNS; ++i) {
+        TYPE term(1);
+        for (size_t j(0); j<ROWS; ++j)
+          term *= at((i+j)%COLUMNS, ROWS-j-1);
+        res -= term;
+      }
+      return res;
     }
-    
-    ///}
 
+    ///}
+    
     //................................................................methods
   protected:
 
@@ -196,18 +230,19 @@ template<typename TYPE, size_t TROWS=0, size_t TCOLUMNS=0> class Matrix:
     /// @name construction
     ///{
     
-    Matrix(): Parent(TROWS, TCOLUMNS) {}
-    
-    template<typename ...ARGS>
-        Matrix(ARGS...t): Parent(TROWS, TCOLUMNS, t...) {
-      static_assert(sizeof...(t)==TROWS*TCOLUMNS,
-                    "wrong array size");
+    Matrix(): Parent(TROWS, TCOLUMNS) {
+      memset(Parent::_c, 0, Parent::MEM_SIZE);
     }
 
     Matrix(const Matrix& o): Matrix() {
       memcpy(Parent::_c, o._c, Parent::MEM_SIZE);
     }
 
+    template<typename ...ARGS>
+        Matrix(ARGS...t): Parent(TROWS, TCOLUMNS, t...) {
+      static_assert(sizeof...(t)==TROWS*TCOLUMNS, "wrong array size");
+    }
+
     ///}
 
     /// @name operators
@@ -218,14 +253,6 @@ template<typename TYPE, size_t TROWS=0, size_t TCOLUMNS=0> class Matrix:
       return *this;
     }
     
-    Matrix<TYPE, TCOLUMNS, TROWS> T() const {
-      Matrix<TYPE, TCOLUMNS, TROWS> res;
-      for (size_t row(0); row<TROWS; ++row)
-        for (size_t column(0); column<TCOLUMNS; ++column)
-          res(column, row) = Parent::operator()(row, column);
-      return res;
-    }
-    
     Matrix operator-() const {
       Matrix res;
       for (TYPE *to((TYPE*)(res._c)+Parent::SIZE); to>(TYPE*)(Parent::_c); --to)
@@ -234,15 +261,30 @@ template<typename TYPE, size_t TROWS=0, size_t TCOLUMNS=0> class Matrix:
     }
 
     template<size_t NEWCOLUMNS>
-        Matrix operator*(const Matrix<TYPE, TCOLUMNS, NEWCOLUMNS>& o) {
+        Matrix<TYPE, TROWS, NEWCOLUMNS>
+        operator*(const Matrix<TYPE, TCOLUMNS, NEWCOLUMNS>& o) const {
       Matrix<TYPE, TROWS, NEWCOLUMNS> res;
       for (size_t i(0); i<TROWS; ++i)
         for (size_t k(0); k<NEWCOLUMNS; ++k)
           for (size_t j(0); j<TCOLUMNS; ++j)
-            res(i, k) += (*this)(i, j) * o(j, k);
+            res(i, k) += this->at(i, j) * o(j, k);
       return res;
     }
+
+    ///}
                     
+    /// @name special operations
+    ///{
+
+    Matrix<TYPE, TCOLUMNS, TROWS> t() const {
+      Matrix<TYPE, TCOLUMNS, TROWS> res;
+      for (size_t row(0); row<TROWS; ++row)
+        for (size_t column(0); column<TCOLUMNS; ++column)
+          res(column, row) = this->at(row, column);
+      return res;
+    }
+
+    ///}
 };
 
 //==============================================================================
@@ -259,12 +301,18 @@ template<typename TYPE> class Matrix<TYPE, 0, 0>: public MatrixBase<TYPE> {
     
     /// @name construction
     ///{
+
+    Matrix() = delete;
     
     Matrix(size_t rows, size_t columns):
         Parent(rows, columns) {
       Parent::_c = new TYPE[rows*columns];
       memset(Parent::_c, 0, Parent::MEM_SIZE);
     }
+
+    Matrix(const Matrix& o): Matrix(o.ROWS, o.Parent::COLUMNS) {
+      memcpy(Parent::_c, o.Parent::_c, Parent::MEM_SIZE);
+    }
     
     template<typename ...ARGS>
         Matrix(size_t rows, size_t columns, ARGS...t):
@@ -273,10 +321,6 @@ template<typename TYPE> class Matrix<TYPE, 0, 0>: public MatrixBase<TYPE> {
       copy_args(Parent::_c, t...);
     }
 
-    Matrix(const Matrix& o): Matrix(o.ROWS, o.Parent::COLUMNS) {
-      memcpy(Parent::_c, o.Parent::_c, Parent::MEM_SIZE);
-    }
-
     ///}
 
     /// @name destruction
@@ -303,11 +347,11 @@ template<typename TYPE> class Matrix<TYPE, 0, 0>: public MatrixBase<TYPE> {
       return Parent::operator=(o);
     }
 
-    Matrix T() const {
+    Matrix t() const {
       Matrix res(Parent::COLUMNS, Parent::ROWS);
       for (size_t row(0); row<Parent::ROWS; ++row)
         for (size_t column(0); column<Parent::COLUMNS; ++column)
-          res(column, row) = Parent::operator()(row, column);
+          res(column, row) = this->at(row, column);
       return res;
     }
 
@@ -318,6 +362,16 @@ template<typename TYPE> class Matrix<TYPE, 0, 0>: public MatrixBase<TYPE> {
       return res;
     }
 
+    Matrix operator*(const Matrix& o) const {
+      Matrix<TYPE> res(this->ROWS, o.COLUMNS);
+      assert(this->COLUMNS==o.ROWS);
+      for (size_t i(0); i<this->ROWS; ++i)
+        for (size_t k(0); k<o.COLUMNS; ++k)
+          for (size_t j(0); j<this->COLUMNS; ++j)
+            res(i, k) += this->at(i, j) * o(j, k);
+      return res;
+    }
+
     ///}
 
     //................................................................methods
@@ -343,6 +397,38 @@ template<typename TYPE> class Matrix<TYPE, 0, 0>: public MatrixBase<TYPE> {
 
 //==============================================================================
 
+template<typename TYPE, size_t ROWS, size_t COLUMNS>
+    Matrix<TYPE, ROWS, COLUMNS> operator+(const Matrix<TYPE, ROWS, COLUMNS>& a,
+                                          const Matrix<TYPE, ROWS, COLUMNS>& b) {
+  Matrix<TYPE, ROWS, COLUMNS> res(a);
+  res += b;
+   return res;
+}
+
+template<typename TYPE, size_t ROWS, size_t COLUMNS>
+    Matrix<TYPE, ROWS, COLUMNS> operator-(const Matrix<TYPE, ROWS, COLUMNS>& a,
+                                          const Matrix<TYPE, ROWS, COLUMNS>& b) {
+  Matrix<TYPE, ROWS, COLUMNS> res(a);
+  res -= b;
+   return res;
+}
+
+template<typename TYPE, size_t ROWS, size_t COLUMNS>
+    Matrix<TYPE, ROWS, COLUMNS> operator*(const TYPE& v,
+                                          const Matrix<TYPE, ROWS, COLUMNS>& m) {
+  Matrix<TYPE, ROWS, COLUMNS> res(m);
+  res *= v;
+   return res;
+}
+
+template<typename TYPE, size_t ROWS, size_t COLUMNS>
+    Matrix<TYPE, ROWS, COLUMNS> operator*(const Matrix<TYPE, ROWS, COLUMNS>& m,
+                                          const TYPE& v) {
+  Matrix<TYPE, ROWS, COLUMNS> res(m);
+  res *= v;
+   return res;
+}
+
 template<typename TYPE, size_t ROWS, size_t COLUMNS>
     std::ostream& operator<<(std::ostream& s, const Matrix<TYPE, ROWS, COLUMNS>& m) {
   for (size_t w = 0; w < m.ROWS; ++w) {
diff --git a/test/basic.cxx b/test/basic.cxx
index fce9437..a678871 100644
--- a/test/basic.cxx
+++ b/test/basic.cxx
@@ -17,8 +17,8 @@ class TemplateMatrixTest: public CppUnit::TestFixture {
   public:
     template<typename T>
         void initFromArray1() {
-      Matrix<T,2,4> m {1, 2, 3, 4,
-                       5, 6, 7, 8};
+      const Matrix<T,2,4> m {1, 2, 3, 4,
+                             5, 6, 7, 8};
       CPPUNIT_ASSERT_EQUAL((T)1, m[0][0]);
       CPPUNIT_ASSERT_EQUAL((T)2, m[0][1]);
       CPPUNIT_ASSERT_EQUAL((T)3, m[0][2]);
@@ -30,8 +30,8 @@ class TemplateMatrixTest: public CppUnit::TestFixture {
     }
     template<typename T>
         void initFromArray2() {
-      Matrix<T,2,4> m(1, 2, 3, 4,
-                      5, 6, 7, 8);
+      const Matrix<T,2,4> m(1, 2, 3, 4,
+                            5, 6, 7, 8);
       CPPUNIT_ASSERT_EQUAL((T)1, m[0][0]);
       CPPUNIT_ASSERT_EQUAL((T)2, m[0][1]);
       CPPUNIT_ASSERT_EQUAL((T)3, m[0][2]);
@@ -43,8 +43,8 @@ class TemplateMatrixTest: public CppUnit::TestFixture {
     }
     template<typename T>
         void initFromArray3() {
-      Matrix<T,2,4> m({1, 2, 3, 4,
-                       5, 6, 7, 8});
+      const Matrix<T,2,4> m({1, 2, 3, 4,
+                             5, 6, 7, 8});
       CPPUNIT_ASSERT_EQUAL((T)1, m[0][0]);
       CPPUNIT_ASSERT_EQUAL((T)2, m[0][1]);
       CPPUNIT_ASSERT_EQUAL((T)3, m[0][2]);
@@ -81,7 +81,7 @@ class TemplateMatrixTest: public CppUnit::TestFixture {
     }
     template<typename T>
         void initFromDefault() {
-      Matrix<T,2,2> m;
+      const Matrix<T,2,2> m;
       CPPUNIT_ASSERT_EQUAL((T)0, m[0][0]);
       CPPUNIT_ASSERT_EQUAL((T)0, m[0][1]);
       CPPUNIT_ASSERT_EQUAL((T)0, m[1][0]);
@@ -105,9 +105,69 @@ class TemplateMatrixTest: public CppUnit::TestFixture {
                        5, 6, 7, 9);
       Matrix<T,2,4> m4(9, 2, 3, 4,
                        5, 6, 7, 8);
+      Matrix<T,2,4> m5(1, 2, 0, 4,
+                       5, 6, 7, 8);
       CPPUNIT_ASSERT(m1==m2);
       CPPUNIT_ASSERT(m1!=m3);
       CPPUNIT_ASSERT(m1!=m4);
+      CPPUNIT_ASSERT(m1!=m5);
+    }
+    template<typename T>
+        void operator_plus() {
+      const Matrix<T,2,4> m1(1, 2, 3, 4,
+                             5, 6, 7, 8);
+      const Matrix<T,2,4> m2(2, 4, 6, 8,
+                             1, 3, 5, 7);
+      const Matrix<T,2,4> m(m1+m2);
+      const Matrix<T,2,4> res(3, 6, 9, 12,
+                              6, 9, 12, 15);
+      CPPUNIT_ASSERT_EQUAL(res, m);
+    }
+    template<typename T>
+        void operator_minus() {
+      const Matrix<T,2,4> m1(1, 2, 3, 4,
+                             5, 6, 7, 8);
+      const Matrix<T,2,4> m2(2, 4, 6, 8,
+                             1, 3, 5, 7);
+      const Matrix<T,2,4> m(m1-m2);
+      const Matrix<T,2,4> res(-1, -2, -3, -4,
+                              4, 3, 2, 1);
+      CPPUNIT_ASSERT_EQUAL(res, m);
+    }
+    template<typename T>
+        void scalar_mult() {
+      const Matrix<T,2,4> m1(1, 2, 3, 4,
+                             5, 6, 7, 8);
+      T two(2), three(3), four(4), big(32);
+      CPPUNIT_ASSERT_EQUAL(m1*two, m1+m1);
+      CPPUNIT_ASSERT_EQUAL(m1*three, m1+m1+m1);
+      CPPUNIT_ASSERT_EQUAL(m1*four, m1+m1+m1+m1);
+      CPPUNIT_ASSERT_EQUAL(two*m1, m1*two);
+      CPPUNIT_ASSERT_EQUAL(three*m1, m1*three);
+      CPPUNIT_ASSERT_EQUAL(four*m1, m1*four);
+      CPPUNIT_ASSERT_EQUAL(two*m1*two, m1*four);
+      CPPUNIT_ASSERT_EQUAL(big*m1*four, m1*four*big);
+    }
+    template<typename T>
+        void matrix_mult() {
+      const Matrix<T,2,3> m1(1, 2, 3,
+                             4, 5, 6);
+      const Matrix<T,3,4> m2(1, 4, 7, 10,
+                             2, 5, 8, 11,
+                             3, 6, 9, 12);
+      const Matrix<T,2,4> m(m1*m2);
+      const Matrix<T,2,4> res(14, 32,  50,  68,
+                              32, 77, 122, 167);
+      CPPUNIT_ASSERT_EQUAL(res, m);
+    }
+    template<typename T>
+        void transpose() {
+      const Matrix<T,2,3> m(1, 2, 3,
+                            4, 5, 6);
+      const Matrix<T,3,2> res(1, 4,
+                              2, 5,
+                              3, 6);
+      CPPUNIT_ASSERT_EQUAL(res, m.t());
     }
     CPPUNIT_TEST_SUITE(TemplateMatrixTest);
     CPPUNIT_TEST(initFromArray1<int>);
@@ -146,6 +206,36 @@ class TemplateMatrixTest: public CppUnit::TestFixture {
     CPPUNIT_TEST(equality<unsigned long>);
     CPPUNIT_TEST(equality<float>);
     CPPUNIT_TEST(equality<double>);
+    CPPUNIT_TEST(operator_plus<int>);
+    CPPUNIT_TEST(operator_plus<long>);
+    CPPUNIT_TEST(operator_plus<unsigned>);
+    CPPUNIT_TEST(operator_plus<unsigned long>);
+    CPPUNIT_TEST(operator_plus<float>);
+    CPPUNIT_TEST(operator_plus<double>);
+    CPPUNIT_TEST(operator_minus<int>);
+    CPPUNIT_TEST(operator_minus<long>);
+    CPPUNIT_TEST(operator_minus<unsigned>);
+    CPPUNIT_TEST(operator_minus<unsigned long>);
+    CPPUNIT_TEST(operator_minus<float>);
+    CPPUNIT_TEST(operator_minus<double>);
+    CPPUNIT_TEST(scalar_mult<int>);
+    CPPUNIT_TEST(scalar_mult<long>);
+    CPPUNIT_TEST(scalar_mult<unsigned>);
+    CPPUNIT_TEST(scalar_mult<unsigned long>);
+    CPPUNIT_TEST(scalar_mult<float>);
+    CPPUNIT_TEST(scalar_mult<double>);
+    CPPUNIT_TEST(matrix_mult<int>);
+    CPPUNIT_TEST(matrix_mult<long>);
+    CPPUNIT_TEST(matrix_mult<unsigned>);
+    CPPUNIT_TEST(matrix_mult<unsigned long>);
+    CPPUNIT_TEST(matrix_mult<float>);
+    CPPUNIT_TEST(matrix_mult<double>);
+    CPPUNIT_TEST(transpose<int>);
+    CPPUNIT_TEST(transpose<long>);
+    CPPUNIT_TEST(transpose<unsigned>);
+    CPPUNIT_TEST(transpose<unsigned long>);
+    CPPUNIT_TEST(transpose<float>);
+    CPPUNIT_TEST(transpose<double>);
     CPPUNIT_TEST_SUITE_END();
 };
 CPPUNIT_TEST_SUITE_REGISTRATION(TemplateMatrixTest);
@@ -241,6 +331,75 @@ class VariableMatrixTest: public CppUnit::TestFixture {
       CPPUNIT_ASSERT(m1!=m3);
       CPPUNIT_ASSERT(m1!=m4);
     }
+    template<typename T>
+        void operator_plus() {
+      const Matrix<T> m1(2, 4,
+                         1, 2, 3, 4,
+                         5, 6, 7, 8);
+      const Matrix<T> m2(2, 4,
+                         2, 4, 6, 8,
+                         1, 3, 5, 7);
+      const Matrix<T> m(m1+m2);
+      const Matrix<T> res(2, 4,
+                          3, 6, 9, 12,
+                          6, 9, 12, 15);
+      CPPUNIT_ASSERT_EQUAL(res, m);
+    }
+    template<typename T>
+        void operator_minus() {
+      const Matrix<T> m1(2, 4,
+                         1, 2, 3, 4,
+                         5, 6, 7, 8);
+      const Matrix<T> m2(2, 4,
+                         2, 4, 6, 8,
+                         1, 3, 5, 7);
+      const Matrix<T> m(m1-m2);
+      const Matrix<T> res(2, 4,
+                         -1, -2, -3, -4,
+                          4, 3, 2, 1);
+      CPPUNIT_ASSERT_EQUAL(res, m);
+    }
+    template<typename T>
+        void scalar_mult() {
+      const Matrix<T> m1(2, 4,
+                         1, 2, 3, 4,
+                         5, 6, 7, 8);
+      T two(2), three(3), four(4), big(32);
+      CPPUNIT_ASSERT_EQUAL(m1*two, m1+m1);
+      CPPUNIT_ASSERT_EQUAL(m1*three, m1+m1+m1);
+      CPPUNIT_ASSERT_EQUAL(m1*four, m1+m1+m1+m1);
+      CPPUNIT_ASSERT_EQUAL(two*m1, m1*two);
+      CPPUNIT_ASSERT_EQUAL(three*m1, m1*three);
+      CPPUNIT_ASSERT_EQUAL(four*m1, m1*four);
+      CPPUNIT_ASSERT_EQUAL(two*m1*two, m1*four);
+      CPPUNIT_ASSERT_EQUAL(big*m1*four, m1*four*big);
+    }
+    template<typename T>
+        void matrix_mult() {
+      const Matrix<T> m1(2, 3,
+                         1, 2, 3,
+                         4, 5, 6);
+      const Matrix<T> m2(3, 4,
+                         1, 4, 7, 10,
+                         2, 5, 8, 11,
+                         3, 6, 9, 12);
+      const Matrix<T> m(m1*m2);
+      const Matrix<T> res(2, 4,
+                          14, 32,  50,  68,
+                          32, 77, 122, 167);
+      CPPUNIT_ASSERT_EQUAL(res, m);
+    }
+    template<typename T>
+        void transpose() {
+      const Matrix<T> m(2, 3,
+                        1, 2, 3,
+                        4, 5, 6);
+      const Matrix<T> res(3, 2,
+                          1, 4,
+                          2, 5,
+                          3, 6);
+      CPPUNIT_ASSERT_EQUAL(res, m.t());
+    }
     CPPUNIT_TEST_SUITE(VariableMatrixTest);
     CPPUNIT_TEST(initFromArray1<int>);
     CPPUNIT_TEST(initFromArray1<long>);
@@ -272,6 +431,42 @@ class VariableMatrixTest: public CppUnit::TestFixture {
     CPPUNIT_TEST(equality<unsigned long>);
     CPPUNIT_TEST(equality<float>);
     CPPUNIT_TEST(equality<double>);
+    CPPUNIT_TEST(operator_plus<int>);
+    CPPUNIT_TEST(operator_plus<long>);
+    CPPUNIT_TEST(operator_plus<unsigned>);
+    CPPUNIT_TEST(operator_plus<unsigned long>);
+    CPPUNIT_TEST(operator_plus<float>);
+    CPPUNIT_TEST(operator_plus<double>);
+    CPPUNIT_TEST(operator_minus<int>);
+    CPPUNIT_TEST(operator_minus<long>);
+    CPPUNIT_TEST(operator_minus<unsigned>);
+    CPPUNIT_TEST(operator_minus<unsigned long>);
+    CPPUNIT_TEST(operator_minus<float>);
+    CPPUNIT_TEST(operator_minus<double>);
+    CPPUNIT_TEST(scalar_mult<int>);
+    CPPUNIT_TEST(scalar_mult<long>);
+    CPPUNIT_TEST(scalar_mult<unsigned>);
+    CPPUNIT_TEST(scalar_mult<unsigned long>);
+    CPPUNIT_TEST(scalar_mult<float>);
+    CPPUNIT_TEST(scalar_mult<double>);
+    CPPUNIT_TEST(scalar_mult<int>);
+    CPPUNIT_TEST(scalar_mult<long>);
+    CPPUNIT_TEST(scalar_mult<unsigned>);
+    CPPUNIT_TEST(scalar_mult<unsigned long>);
+    CPPUNIT_TEST(scalar_mult<float>);
+    CPPUNIT_TEST(scalar_mult<double>);
+    CPPUNIT_TEST(matrix_mult<int>);
+    CPPUNIT_TEST(matrix_mult<long>);
+    CPPUNIT_TEST(matrix_mult<unsigned>);
+    CPPUNIT_TEST(matrix_mult<unsigned long>);
+    CPPUNIT_TEST(matrix_mult<float>);
+    CPPUNIT_TEST(matrix_mult<double>);
+    CPPUNIT_TEST(transpose<int>);
+    CPPUNIT_TEST(transpose<long>);
+    CPPUNIT_TEST(transpose<unsigned>);
+    CPPUNIT_TEST(transpose<unsigned long>);
+    CPPUNIT_TEST(transpose<float>);
+    CPPUNIT_TEST(transpose<double>);
     CPPUNIT_TEST_SUITE_END();
 };
 CPPUNIT_TEST_SUITE_REGISTRATION(VariableMatrixTest);