TheRock/rocm-libraries/projects/rocsparse/clients/common/rocsparse_vector_utils.cpp

/*! \file */
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 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
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 *
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#include "rocsparse_vector_utils.hpp"

#include <algorithm>

/*! \brief Perform max norm on an array of complex values. */
template <typename T,
          typename std::enable_if<(std::is_same<T, rocsparse_float_complex>::value
                                   || std::is_same<T, rocsparse_double_complex>::value),
                                  int>::type
          = 0>
static void normalize_array(T* v, size_t v_size)
{
    if(v_size > 0)
    {
        auto max_val = std::abs(v[0]);

        for(size_t i = 1; i < v_size; i++)
        {
            max_val = std::max(std::abs(v[i]), max_val);
        }

        auto factor = static_cast<floating_data_t<T>>(1) / max_val;

        for(size_t i = 0; i < v_size; i++)
        {
            v[i] *= factor;
        }
    }
}

/*! \brief Perform affine transform of bound [-1, 1] on an array of real values. */
template <typename T,
          typename std::enable_if<(std::is_same<T, float>::value || std::is_same<T, double>::value),
                                  int>::type
          = 0>
static void normalize_array(T* v, size_t v_size)
{
    if(v_size > 0)
    {
        auto max_val = v[0];
        auto min_val = v[0];

        for(size_t i = 1; i < v_size; i++)
        {
            max_val = std::max(v[i], max_val);
            min_val = std::min(v[i], min_val);
        }

        if(std::abs(max_val - min_val) > std::numeric_limits<T>::epsilon() * max_val)
        {
            // y = (2x - max - min) / (max - min)
            auto denom = static_cast<T>(1) / (max_val - min_val);

            for(size_t i = 0; i < v_size; i++)
            {
                v[i] = (2 * v[i] - max_val - min_val) * denom;
            }
        }
        else
        {
            auto denom = static_cast<T>(1) / std::max(std::abs(max_val), std::abs(min_val));

            for(size_t i = 0; i < v_size; i++)
            {
                v[i] *= denom;
            }
        }
    }
}

template <typename T>
void rocsparse_vector_utils<T>::normalize(host_dense_vector<T>& v)
{
    normalize_array<T>(v.data(), v.size());
}

template <typename T>
void rocsparse_vector_utils<T>::normalize(host_vector<T>& v)
{
    normalize_array<T>(v.data(), v.size());
}

#define INSTANTIATE(TYPE) template struct rocsparse_vector_utils<TYPE>;

INSTANTIATE(float);
INSTANTIATE(double);
INSTANTIATE(rocsparse_float_complex);
INSTANTIATE(rocsparse_double_complex);

#undef INSTANTIATE