compute_source_index_and_lambda Class — pytorch Architecture

Source Code

aten/src/ATen/native/UpSample.h lines 449–475

template<typename scalar_t, typename opmath_t>
inline void compute_source_index_and_lambda(
    int64_t& input_index0,
    int64_t& input_index1,
    scalar_t& lambda0,
    scalar_t& lambda1,
    opmath_t ratio,
    int64_t output_index,
    int64_t input_size,
    int64_t output_size,
    bool align_corners) {
  if (output_size == input_size) {
    // scale_factor = 1, simply copy
    input_index0 = output_index;
    input_index1 = output_index;
    lambda0 = static_cast<scalar_t>(1);
    lambda1 = static_cast<scalar_t>(0);
  } else {
    const auto real_input_index =
        area_pixel_compute_source_index<opmath_t>(
            ratio, output_index, align_corners, /*cubic=*/false);
    guard_index_and_lambda(real_input_index, input_size, input_index0, lambda1);
    int64_t offset = (input_index0 < input_size - 1) ? 1 : 0;
    input_index1 = input_index0 + offset;
    lambda0 = static_cast<scalar_t>(1.) - lambda1;
  }
}