int main(void) { // Create a valarray of ints. valarray_t::value_type ibuf[27] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 }; valarray_t vi(ibuf, 27); // Create length and stride valarray selector_t::value_type length_buf[3] = {3,3,3}; selector_t::value_type stride_buf[3] = {9,3,1}; selector_t length_val(length_buf, 3); selector_t stride_val(stride_buf, 3); // Print out the valarray<int>. std::cout << "original valarray vi\n\n" << vi << "\n\n"; // Print out all three dimensions (the entire valarray). std::cout << "vi[gslice(0,{3,3,3},{9,3,1})]\n\n" << vi[std::gslice(0,length_val,stride_val)] << "\n\n"; // Print a two dimensional slice out of the middle. selector_t::value_type length_buf2[] = {3, 3}; selector_t::value_type stride_buf2[] = {3, 1}; selector_t length_val2(length_buf2, 2); selector_t stride_val2(stride_buf2, 2); std::cout << "vi[gslice(9,{3,3},{3,1})]\n\n" << vi[std::gslice(9,length_val2,stride_val2)] << "\n\n"; // Print another two dimensional slice out of the middle but // orthoganal to one we just did. stride_val2[0] = 9; stride_val2[1] = 1; std::cout << "vi[gslice(3,{3,3},{9,1})]\n\n" << vi[std::gslice(3,length_val2,stride_val2)] << "\n\n"; // Print out the last plane in the middle -- orthoganal to both // of the previous ones. stride_val2[0] = 3; stride_val2[1] = 9; std::cout << "vi[gslice(1,{3,3},{3,9})]\n\n" << vi[std::gslice(1,length_val2,stride_val2)] << "\n\n"; // Now how about a diagonal slice, upper left front to lower right // back. stride_val2[0] = 3; stride_val2[1] = 10; std::cout << "vi[gslice(0,{3,3},{3,10})]\n\n" << vi[std::gslice(0,length_val2,stride_val2)] << "\n\n"; return 0; }
int main(void) { valarray_t::value_type ibuf[22] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 }; // Create a valarray of ints valarray_t vi (ibuf,(sizeof ibuf / sizeof *ibuf)); // Print out the valarray std::cout << "original valarray vi:\n\n" << vi << "\n\n"; // Get a two dimensional diagonal slice out of the middle std::size_t length_ary[] = {4, 2}; std::size_t stride_ary[] = {4, 6}; std::valarray<std::size_t> length_val(length_ary, 2); std::valarray<std::size_t> stride_val(stride_ary, 2); // Print out the slices starting at positions 0 and 2 and respectively. std::cout << "vi[gslice(0,[4,2],[4,6])]\n\n" << vi[std::gslice(0,length_val,stride_val)] << "\n\n"; std::cout << "vi[gslice(2,[4,2],[4,6])]\n\n" << vi[std::gslice(2,length_val,stride_val)] << "\n\n"; // Multiply the first slice by the second. vi[std::gslice(0,length_val,stride_val)] *= static_cast<valarray_t > (vi[std::gslice(2,length_val,stride_val)]); std::cout << "vi[gslice(0,[4,2],[4,8])] *= vi[gslice(2,[4,2],[4,6])]\n\n" << vi << std::endl; return 0; }