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std::abs(std::valarray)

From cppreference.com
< cpp‎ | numeric‎ | valarray
 
 
Numerics library
 
std::valarray
 
Defined in header <valarray>
template< class T >
valarray<T> abs( const valarray<T>& va );

Computes absolute value of each element in the value array.

[edit] Parameters

va - value array to apply the operation to

[edit] Return value

Value array containing absolute values of the values in va.

[edit] Notes

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

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

[edit] Possible implementation

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

[edit] Example

Run this code
#include <iostream>
#include <valarray>
 
int main()
{
 std::valarray <int> v{1, -2, 3, -4, 5, -6, 7, -8};
 std::valarray <int> v2 = std::abs(v);
 for (auto n : v2)
 std::cout << n << ' ';
 std::cout << '\n';
}

Output:

1 2 3 4 5 6 7 8

[edit] See also

computes absolute value of an integral value (\(\small{|x|}\)|x|)
(function) [edit]
absolute value of a floating point value (\(\small{|x|}\)|x|)
(function) [edit]
returns the magnitude of a complex number
(function template) [edit]
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