Hi I'm having a problem with the boost/multi_array and I'm hoping someone here can help, or at least explain why the following doesn't work. The problem: I have a multi_array of ints that I want to be able to view as being either row major or column major to simplify a number algorithms. I don't want to change the internal representation of the array (the default c++ row major storage layout is fine), I just want to be able to interchange the indexing order from array[row][col] to array[col][row] for the same multi_array. To do so, I attempted to define 2 array_views of the same multi_array with different stride values, like this: #include <iostream> using namespace std; #include using namespace boost; int main(void) { typedef multi_array intarray2; typedef intarray2::array_view<2>::type intarray2view2; typedef intarray2::array_view<1>::type intarray2view1; typedef intarray2::index_range intarray2range; intarray2 arr(extents[3][3]); // test data int a = 0; for (int r = 0; r < 3; r++) { for (int c = 0; c < 3; c++) { arr[r][c] = a++; } } intarray2view2 rows = arr[indices[intarray2range().stride(3)][intarray2range().stride(1)]]; intarray2view2 cols = arr[indices[intarray2range().stride(1)][intarray2range().stride(3)]]; /* 0 1 2 3 4 5 6 7 8 */ cout << rows[2][1]; // i expect this to print 7 cout << cols[2][1]; // i expect this to print 5 } Unfortunately, this doesn't work at all (an assert fails when indexing the views). I debugged (using Visual C 2005), and found that the 'rows' array_view has a stride collection of [9, 1], while the 'cols' array_view stride collection is [3, 3]. Both are different than what I specified during construction. It appears that they're being multiplied by the extents of the first dimension of the multi_view array (in this example: 3). I can produce a column major view of a single column of the array using a 1 dimensional view constructed using a degenerate range, like this: intarray2view1 col= arr[indices[1][intarray2range()]]; // column 1 in arr but that's not what I'm hoping to achieve. Can someone explain the behavior above and/or suggest a way of creating a 2d column major array_view of a 2d multi_array? Thanks - Chris Dion _________________________________________________________________ Show Your Messenger Buddies How You Really Feel http://www.freemessengeremoticons.ca/?icid=EMENCA122