function template
<valarray>

std::log10

template<class T> valarray<T> log10 (const valarray<T>& x);
Compute common logarithm of valarray elements
Returns a valarray containing the common logarithm (base-10 logarithm) of all the elements of x, in the same order.

The function calls log10 (unqualified) once for each element.

This function overloads cmath's log10.

Parameters

x
valarray containing elements of a type for which the unary function log10 is defined.

Return value

A valarray object with the common logarithms of the elements of x.

Example

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// log10 valarray example
#include <iostream>     // std::cout
#include <cstddef>      // std::size_t
#include <cmath>        // std::log10(double)
#include <valarray>     // std::valarray, std::log10(valarray)

int main ()
{
  double val[] = {1.0, 10.0, 100.0, 200.0};
  std::valarray<double> foo (val,4);

  std::valarray<double> bar = log10 (foo);

  std::cout << "foo:";
  for (std::size_t i=0; i<foo.size(); ++i)
    std::cout << ' ' << foo[i];
  std::cout << '\n';

  std::cout << "bar:";
  for (std::size_t i=0; i<bar.size(); ++i)
    std::cout << ' ' << bar[i];
  std::cout << '\n';

  return 0;
}

Output:

foo: 1 10 100 200
bar: 0 1 2 2.30103


See also