std::log10(std::valarray)

Header: <valarray>

For each element in va computes common (base 10) logarithm of the value of the element.

# Declarations

template< class T >
valarray<T> log10( const valarray<T>& va );

# Parameters

# Return value

Value array containing common logarithms of the values in va.

# Notes

Unqualified function (log10) is used to perform the computation. If such function is not available, std::log10 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:

# Example

#include <cmath>
#include <iomanip>
#include <iostream>
#include <valarray>
 
void show(char const* title, const std::valarray<float>& va)
{
    std::cout << title << " : " << std::right;
    for (float x : va)
        std::cout << std::setw(6) << x;
    std::cout << '\n';
}
 
int main()
{
    const std::valarray<float> n{-2.f, -1.f, 0.f, 1.f, 2.f, 3.f, INFINITY};
    const std::valarray<float> pow10{std::pow(10.f, n)};
    const std::valarray<float> log10_pow10{std::log10(pow10)};
 
    show("n      ", n);
    show("10ⁿ    ", pow10);
    show("lg(10ⁿ)", log10_pow10);
}

# See also