Function length_squared

dlib/svm/sparse_vector.h:376–392

    template <typename T>
    typename T::value_type::second_type length_squared (
        const T& a
    )
    {
        typedef typename T::value_type::second_type scalar_type;

        typename T::const_iterator i;

        scalar_type sum = 0;

        for (i = a.begin(); i != a.end(); ++i)
        {
            sum += i->second * i->second;
        }

        return sum;
    }

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