fixed memory leak in assignement

Numeric/fullMatrix.h

@@ -97,8 +97,14 @@ class fullMatrix
     if(this != &other){
       _r = other._r; 
       _c = other._c;
-      _data = new scalar[_r * _c];
-      for(int i = 0; i < _r * _c; ++i) _data[i] = other._data[i];
+      if (_data) delete[] _data;
+      if ((_r==0)||(_c==0))
+        _data=0;
+      else
+      {
+        _data = new scalar[_r * _c];
+        for(int i = 0; i < _r * _c; ++i) _data[i] = other._data[i];
+      }
     }
     return *this;
   }