C++ Valarray::exp Function

The class used to represent and work with value arrays is called std::valarray. It provides a variety of generalized subscript operators, slicing, and indirect access in addition to element-wise mathematical operations.

The C++ Valarray::exp() function is used to compute e raised to the power of the value of the element in the valarray. Each element receives a single call to this method, which overloads with cmath's exp() function.

Syntax

Following is the syntax for C++ Valarray::exp Function −

exp (const valarray<T>& x);

Parameters

x − It is containing elements of a type for which the unary function exp is defined.

Examples

Example 1

Let's look into the following example, where we are going to use exp() function and retrieving the output.

#include <iostream>
#include <valarray>
using namespace std;

int main() {
   valarray<double>
   varr = { 4,6,8,10,11 };
   valarray<double> varr1;
   varr1 = exp(varr);
   cout << "The New exp"
      << " Valarray is : "
      << endl;
   for (double& x : varr1) {
      cout << x << " ";
   }
   cout << endl;
   return 0;
}

Output

Let us compile and run the above program, this will produce the following result −

The New exp Valarray is : 
54.5982 403.429 2980.96 22026.5 59874.1 

Example 2

Let's consider the following example, where we are going to use exp() function and retrieving the output with both original valarray and exp valarray.

#include <iostream>
#include <valarray>
using namespace std;

int main() {
   valarray<double> myvalarray = { 1.2, -0.46, -1.5, 0.45, -1.23 };
   cout << "The Orignal Valarray is : ";
   
   for (double& ele : myvalarray)
      cout << ele << " ";
   valarray<double> expValarray;
   expValarray = exp(myvalarray);
   cout << "\nThe exp Valarray is : ";
   
   for (double& ele : expValarray)
      cout << ele << " ";
   return 0;
}

Output

Let us compile and run the above program, this will produce the following result −

The Orignal Valarray is : 1.2 -0.46 -1.5 0.45 -1.23 
The exp Valarray is : 3.32012 0.631284 0.22313 1.56831 0.292293   

Example 3

In the following example, we are going to consider the basic example of the usage of the exp() function.

#include <stdio.h>
#include <math.h>

int main () {
   double a, result;
   a = 2.3;
   result = exp (a);
   printf ("The exp value of %f is %f.\n", a, result );
   return 0;
}

Output

Let us compile and run the above program, this will produce the following result −

The exp value of 2.300000 is 9.974182.