C++ <valarray> - log() Function
The C++ <valarray> log() function returns a valarray containing natural logarithm (base-e logarithm) value of all the elements of valarray va, in the same order. This function overloads with cmath's log() function and calls this function once for each element.
Syntax
template<class T> valarray<T> log (const valarray<T>& va);
Parameters
va |
Specify valarray containing elements of a type for which the function log() is defined. |
Return Value
Returns valarray containing natural logarithm (base-e logarithm) value of all the elements of va.
Example:
The example below shows the usage of log() function.
#include <iostream>
#include <valarray>
using namespace std;
int main (){
valarray<double> va1 = {1, 2, 3, 4};
//va2 will contain log of all elements of va1
valarray<double> va2 = log(va1);
cout<<fixed;
cout<<"va1 contains: ";
for(int i = 0; i < va1.size(); i++)
cout<<va1[i]<<" ";
cout<<"\nva2 contains: ";
for(int i = 0; i < va2.size(); i++)
cout<<va2[i]<<" ";
return 0;
}
The output of the above code will be:
va1 contains: 1.000000 2.000000 3.000000 4.000000 va2 contains: 0.000000 0.693147 1.098612 1.386294
❮ C++ <valarray> Library
