std::log(std::valarray)

Defined in header <valarray>
template< class T >
valarray<T> log( const valarray<T>& va );

For each element in va computes natural logarithm of the value of the element.

Parameters

va - value array to apply the operation to

Return value

Value array containing natural logarithms of the values in va.

Notes

Unqualified function (log) is used to perform the computation. If such function is not available, std::log is used due to argument dependent lookup.

The function can be implemented with the return type different from std::valarray. In this case, the replacement type has the following properties:

Possible implementation

template< class T >
valarray<T> log( const valarray<T>& va )
{
    valarray<T> other = va;
    for (T &i : other) {
        i = log(i);
    }
    return other;
}

Example

See also

applies the function std::log10 to each element of valarray
(function template)
applies the function std::exp to each element of valarray
(function template)
(C++11)(C++11)
computes natural (base e) logarithm (ln(x))
(function)
complex natural logarithm with the branch cuts along the negative real axis
(function template)

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