std::log(std::valarray) (3) - Linux Manuals

std::log(std::valarray): std::log(std::valarray)

NAME

std::log(std::valarray) - std::log(std::valarray)

Synopsis


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:


      * All const member functions of std::valarray are provided.
      * std::valarray, std::slice_array, std::gslice_array, std::mask_array and std::indirect_array can be constructed from the replacement type.
      * All functions accepting an argument of type const std::valarray&
        except begin() and end()
        (since C++11) should also accept the replacement type.
      * All functions accepting two arguments of type const std::valarray& should accept every combination of const std::valarray& and the replacement type.
      * The return type does not add more than two levels of template nesting over the most deeply-nested argument type.

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


 This section is incomplete
 Reason: no example

See also


                     applies the function std::log10 to each element of valarray
log10(std::valarray) (function template)
                     applies the function std::exp to each element of valarray
exp(std::valarray) (function template)


log
logf
logl computes natural (base e) logarithm (ln(x))
                     (function)


(C++11)
(C++11)
                     complex natural logarithm with the branch cuts along the negative real axis
log(std::complex) (function template)

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