Difference between revisions of "cpp/numeric/valarray/abs"
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Andreas Krug (Talk | contribs) m (fmt, {{c}}, headers sorted) |
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{{cpp/title|abs{{small|(std::valarray)}}}} | {{cpp/title|abs{{small|(std::valarray)}}}} | ||
| − | {{cpp/numeric/valarray/ | + | {{cpp/numeric/valarray/navbar}} |
| − | {{ddcl | header=valarray | 1= | + | {{ddcl|header=valarray|1= |
template< class T > | template< class T > | ||
valarray<T> abs( const valarray<T>& va ); | valarray<T> abs( const valarray<T>& va ); | ||
}} | }} | ||
| − | Computes absolute value of each element in the value array | + | Computes absolute value of each element in the value array. |
===Parameters=== | ===Parameters=== | ||
| − | {{ | + | {{par begin}} |
| − | {{ | + | {{par|va|value array to apply the operation to}} |
| − | {{ | + | {{par end}} |
===Return value=== | ===Return value=== | ||
| − | Value array containing absolute values of the values in {{ | + | Value array containing absolute values of the values in {{c|va}}. |
===Notes=== | ===Notes=== | ||
| − | {{cpp/numeric/valarray/notes|abs}} | + | {{cpp/numeric/valarray/notes unq|abs}} |
| − | === | + | {{cpp/numeric/valarray/notes ret|abs}} |
| − | {{ | + | |
| − | + | ===Possible implementation=== | |
| − | + | {{cpp/numeric/valarray/impl|abs}} | |
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | + | ||
| − | }} | + | |
===Example=== | ===Example=== | ||
| − | {{example | + | {{example |
|code= | |code= | ||
| + | #include <iostream> | ||
#include <valarray> | #include <valarray> | ||
| − | + | ||
int main() | int main() | ||
{ | { | ||
std::valarray<int> v{1, -2, 3, -4, 5, -6, 7, -8}; | std::valarray<int> v{1, -2, 3, -4, 5, -6, 7, -8}; | ||
std::valarray<int> v2 = std::abs(v); | std::valarray<int> v2 = std::abs(v); | ||
| − | for(auto n : v2) | + | for (auto n : v2) |
std::cout << n << ' '; | std::cout << n << ' '; | ||
std::cout << '\n'; | std::cout << '\n'; | ||
| Line 50: | Line 43: | ||
===See also=== | ===See also=== | ||
| − | {{ | + | {{dsc begin}} |
| − | {{ | + | {{dsc inc|cpp/numeric/math/dsc abs}} |
| − | {{ | + | {{dsc inc|cpp/numeric/math/dsc fabs}} |
| − | {{ | + | {{dsc inc|cpp/numeric/complex/dsc abs}} |
| − | {{ | + | {{dsc end}} |
| + | |||
| + | {{langlinks|de|es|fr|it|ja|pt|ru|zh}} | ||
Latest revision as of 23:43, 16 October 2023
| Defined in header <valarray>
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| template< class T > valarray<T> abs( const valarray<T>& va ); |
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Computes absolute value of each element in the value array.
Contents |
[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:
- All const member functions of std::valarray are provided.
- std::valarray, std::slice_array, std::gslice_array, std::mask_array and std::indirect_array can be constructed from the replacement type.
- For every function taking a const std::valarray<T>& except begin() and end()(since C++11), identical functions taking the replacement types shall be added;
- For every function taking two const std::valarray<T>& arguments, identical functions taking every combination of const std::valarray<T>& and replacement types shall be added.
- The return type does not add more than two levels of template nesting over the most deeply-nested argument type.
[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
| (C++11) |
computes absolute value of an integral value (|x|) (function) |
| (C++11)(C++11) |
absolute value of a floating point value (|x|) (function) |
| returns the magnitude of a complex number (function template) |
