Method collapse

arm_compute/core/Dimensions.h:162–182

Collapse dimensions. * * @param[in] n Number of dimensions to collapse into @p first. * @param[in] first Dimensions into which the following @p n are collapsed. */

     * @param[in] first Dimensions into which the following @p n are collapsed.
     */
    void collapse(const size_t n, const size_t first = 0)
    {
        ARM_COMPUTE_ERROR_ON(first + n > _id.size());

        const size_t last = std::min(_num_dimensions, first + n);

        if (last > (first + 1))
        {
            auto it_first = _id.begin() + first;
            auto it_last  = _id.begin() + last;
            // Collapse dimensions into the first
            _id[first] = std::accumulate(it_first, it_last, T(1), std::multiplies<T>());
            // Shift the remaining dimensions down
            std::copy(it_last, _id.begin() + _num_dimensions, it_first + 1);
            // Reduce the number of dimensions
            const size_t old_num_dimensions = _num_dimensions;
            _num_dimensions -= last - first - 1;
            // Fill the now empty dimensions with zero
            std::fill(_id.begin() + _num_dimensions, _id.begin() + old_num_dimensions, 0);
        }
    }

    /** Collapse dimensions starting from a given point
     *