valarray log() function in C++ Last Updated : 24 Oct, 2018 Comments Improve Suggest changes 1 Likes Like Report The log() function is defined in valarray header file. This function is used to calculate natural logarithm of the value of the elements in valarray. Syntax: log(varr); Parameter: This function takes a mandatory parameter varr which represents valarray. Returns: This function returns a valarray containing the natural logarithm of all the elements. Below programs illustrate the above function: Example 1:- CPP // C++ program to demonstrate // example of log() function. #include<bits/stdc++.h> using namespace std; int main() { // Initializing valarray valarray<double> varr = { 1, 2, 3, 4, 5 }; // Declaring new valarray valarray<double> varr1 ; // use of log() function varr1 = log(varr); // Displaying new elements value cout << "The new valarray with" << " manipulated values is : " << endl; for (double& x : varr1) { cout << x << " "; } cout << endl; return 0; } Output: The new valarray with manipulated values is : 0 0.693147 1.09861 1.38629 1.60944 Example 2:- CPP // C++ program to demonstrate // example of log() function. #include<bits/stdc++.h> using namespace std; int main() { // Initializing valarray valarray<double> varr = { -1, 6, 3, 45, 5 }; // Declaring new valarray valarray<double> varr1 ; // use of log() function varr1 = log(varr); // Displaying new elements value cout << "The new valarray with" << " manipulated values is : " << endl; for (double& x : varr1) { cout << x << " "; } cout << endl; return 0; } Output: The new valarray with manipulated values is : nan 1.79176 1.09861 3.80666 1.60944 Create Quiz Comment B bansal_rtk_ Follow 1 Improve B bansal_rtk_ Follow 1 Improve Article Tags : Misc C++ CPP-Functions cpp-valarray Explore C++ BasicsIntroduction to C++3 min readData Types in C++6 min readVariables in C++4 min readOperators in C++9 min readBasic Input / Output in C++3 min readControl flow statements in Programming15+ min readLoops in C++7 min readFunctions in C++8 min readArrays in C++8 min readCore ConceptsPointers and References in C++5 min readnew and delete Operators in C++ For Dynamic Memory5 min readTemplates in C++8 min readStructures, Unions and Enumerations in C++3 min readException Handling in C++12 min readFile Handling in C++8 min readMultithreading in C++8 min readNamespace in C++5 min readOOP in C++Object Oriented Programming in C++8 min readInheritance in C++6 min readPolymorphism in C++5 min readEncapsulation in C++3 min readAbstraction in C++4 min readStandard Template Library(STL)Standard Template Library (STL) in C++3 min readContainers in C++ STL2 min readIterators in C++ STL10 min readC++ STL Algorithm Library3 min readPractice & ProblemsC++ Interview Questions and Answers1 min readC++ Programming Examples4 min read Like