function template
<valarray>
std::pow
template<class T> valarray<T> pow (const valarray<T>& x, const valarray<T>& y);template<class T> valarray<T> pow (const valarray<T>& x, const T& y);template<class T> valarray<T> pow (const T& x, const valarray<T>& y);
Compute power of valarray elements
Returns a valarray containing the results of the power operation on all the elements, in the same order. The results calculated are x raised to the power y (xy).
The function calls pow (unqualified) once for each element in both x and y; If either is a single T value, it is used for all calls.
This function overloads cmath's pow.
Parameters
- x
- valarray or element with the bases for the power operations.
- y
- valarray or element with the exponents for the power operations.
If both arguments are valarray objects and their sizes don't match, the behavior is undefined.
Return value
A valarray object with the values of x to the power of y.
Example
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// pow valarray example
#include <iostream> // std::cout
#include <cstddef> // std::size_t
#include <cmath> // std::pow
#include <valarray> // std::valarray, std::pow
int main ()
{
std::valarray<double> val (5);
std::valarray<double> results;
for (int i=0; i<5; ++i) val[i]=i+1;
std::cout << "val:";
for (std::size_t i=0; i<val.size(); ++i) std::cout << ' ' << val[i];
std::cout << '\n';
results = std::pow (val,val);
std::cout << "val^val:";
for (std::size_t i=0; i<results.size(); ++i) std::cout << ' ' << results[i];
std::cout << '\n';
results = std::pow (val,2.0);
std::cout << "val^2:";
for (std::size_t i=0; i<results.size(); ++i) std::cout << ' ' << results[i];
std::cout << '\n';
results = std::pow (2.0,val);
std::cout << "2^val:";
for (std::size_t i=0; i<results.size(); ++i) std::cout << ' ' << results[i];
std::cout << '\n';
return 0;
}
Output:
val: 1 2 3 4 5
val^val: 1 4 27 256 3125
val^2: 1 4 9 16 25
2^val: 2 4 8 16 32
See also
- pow (cmath)
- Raise to power (function)
- log
- Compute natural logarithm of valarray elements (function template)
- exp
- Compute exponential of valarray elements (function template)
- sqrt
- Compute square root of valarray elements (function template)