std::valarray
STD：：valArray
| Defined in header | | |
|---|---|---|
| template< class T > class valarray; | | |
std::valarray用于表示和操作值数组的类。它支持按元素划分的数学运算和各种形式的广义下标算子、切片和间接访问.
注记
std::valarray助手类被定义为不受某些形式的混叠，从而使这些类上的操作能够像关键字的效果一样得到优化。限制用C语言编程。此外，函数和操作符valarray参数可以返回代理对象，使编译器能够优化表达式，如v1 = a*v2 + v3;作为一个执行v1[i] = a*v2[i] + v3[i];避免任何临时人员或多次通行证。然而，表达式模板为任何C++容器提供相同的优化技术，大多数数字库更喜欢表达式模板而不是值数组，以获得灵活性。一些C++标准库实现使用表达式模板来实现对std::valarray%28等。GNU libstdc++和LLVM libc++%29。只是很少有值数组被进一步优化，例如。英特尔并行工作室...
模板参数
| T | - | the type of the elements. The type must meet the NumericType requirements |
|---|
成员类型
| Member type | Definition |
|---|---|
| value_type | T |
成员函数
| (constructor) | constructs new numeric array (public member function) |
|---|---|
| (destructor) | destructs the numeric array (public member function) |
| operator= | assigns the contents (public member function) |
| operator[] | get/set valarray element, slice, or mask (public member function) |
| operator+operator-operator~operator! | applies a unary arithmetic operator to each element of the valarray (public member function) |
| operator+=operator-=operator*=operator/=operator%=operator&=operator|=operator^=operator<<=operator>>= | applies compound assignment operator to each element of the valarray (public member function) |
| swap | swaps with another valarray (public member function) |
| size | returns the size of valarray (public member function) |
| resize | changes the size of valarray (public member function) |
| sum | calculates the sum of all elements (public member function) |
| min | returns the smallest element (public member function) |
| max | returns the largest element (public member function) |
| shift | zero-filling shift the elements of the valarray (public member function) |
| cshift | circular shift of the elements of the valarray (public member function) |
| apply | applies a function to every element of a valarray (public member function) |
非会员职能
| std::swap(std::valarray) (C++11) | specializes the std::swap() algorithm (function template) |
|---|---|
| std::begin(std::valarray) (C++11) | specializes std::begin (function template) |
| std::end(std::valarray) (C++11) | specializes std::end (function template) |
| operator+operator-operator*operator/operator%operator&operator|operator^operator<<operator>>operator&&operator|| | applies binary operators to each element of two valarrays, or a valarray and a value (function template) |
| operator==operator!=operator<operator<=operator>operator>= | compares two valarrays or a valarray with a value (function template) |
| abs(std::valarray) | applies the function std::abs to each element of valarray (function template) |
指数函数
Exp%28std：：valArray%29将函数std：：exp应用于valArray%28函数模板%29的每个元素
log%28std：：valArray%29将函数std：：log应用于valArray%28函数模板%29的每个元素
log 10%28std：：valArray%29将函数std：：log 10应用于valArray%28函数模板%29的每个元素
幂函数
POW%28std：：valArray%29将函数std：：pow应用于两个valArray或valArray和值%28的函数模板%29
sqrt%28std：：valArray%29将函数std：：sqrt应用于valArray%28函数模板%29的每个元素
三角函数
sin%28 std：：valArray%29将函数std：：sin应用于valArray%28函数模板%29的每个元素
Cos%28std：：valArray%29将函数std：：cos应用于valArray%28函数模板%29的每个元素
Tan%28 std：：valArray%29将函数std：：Tan应用于valArray%28函数模板%29的每个元素
Asin%28std：：valArray%29将函数std：：asin应用于valArray%28函数模板%29的每个元素
ACOS%28std：：valArray%29将函数std：：acos应用于valArray%28函数模板%29的每个元素
Atan%28std：：valArray%29将函数std：：atan应用于valArray%28函数模板%29的每个元素
atan 2%28std：：valArray%29将函数std：：atan 2应用于valArray，并将值%28的函数模板%29应用于valArray。
双曲函数
Sinh%28std：：valArray%29将函数std：：sinh应用于valArray%28函数模板%29的每个元素
COSH%28std：：valArray%29将函数std：：cosh应用于valArray%28函数模板%29的每个元素
Tanh%28std：：valArray%29将函数std：：tanh应用于valArray%28函数模板%29的每个元素
帮助者类
| slice | BLAS-like slice of a valarray: starting index, length, stride (class) |
|---|---|
| slice_array | proxy to a subset of a valarray after applying a slice (class template) |
| gslice | generalized slice of a valarray: starting index, set of lengths, set of strides (class) |
| gslice_array | proxy to a subset of a valarray after applying a gslice (class template) |
| mask_array | proxy to a subset of a valarray after applying a boolean mask operator |
| indirect_array | proxy to a subset of a valarray after applying indirect operator |
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