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      std::log10(std::valarray)

      From cppreference.com
      <cpp‎ |numeric‎ |valarray
       
       
       
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      Defined in header<valarray>
      template<class T>
      valarray<T> log10(const valarray<T>& va);

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

      Contents

      [edit]Parameters

      va - value array to apply the operation to

      [edit]Return value

      Value array containing common logarithms of the values inva.

      [edit]Notes

      Unqualified function (log10) is used to perform the computation. If such function is not available,std::log10 is used due toargument-dependent lookup.

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

      [edit]Possible implementation

      template<class T>valarray<T> log10(const valarray<T>& va){    valarray<T> other= va;for(T& i: other)        i= log10(i); return other;// proxy object may be returned}

      [edit]Example

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

      Output:

      n       :     -2    -1     0     1     2     3   inf10ⁿ     :   0.01   0.1     1    10   100  1000   inflg(10ⁿ) :     -2    -1     0     1     2     3   inf

      [edit]See also

      applies the functionstd::log to each element of valarray
      (function template)[edit]
      (C++11)(C++11)
      computes common (base10) logarithm (\({\small\log_{10}{x}}\)log10(x))
      (function)[edit]
      complex common logarithm with the branch cuts along the negative real axis
      (function template)[edit]
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/numeric/valarray/log10&oldid=160810"

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