std::log10(std::complex)

 

C++

语言

标准库头文件

自立与有宿主实现

具名要求

语言支持库

概念库 (C++20)

诊断库

工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

输入/输出库

本地化库

正则表达式库 (C++11)

原子操作库 (C++11)

线程支持库 (C++11)

文件系统库 (C++17)

技术规范

 

数值库

常用数学函数

数学特殊函数 (C++17)

数学常数 (C++20)

浮点环境 (C++11)

复数

数值数组

伪随机数生成

编译时有理数算术 (C++11)

数值算法

gcd (C++17)

lcm (C++17)

插值

midpoint (C++20)

lerp (C++20)

通用数值运算

iota (C++11)

accumulate

inner_product

adjacent_difference

partial_sum

位操作

bit_cast (C++20)

ispow2 (C++20)

ceil2 (C++20)

floor2 (C++20)

log2p1 (C++20)

rotl (C++20)

rotr (C++20)

countl_zero (C++20)

countl_one (C++20)

countr_zero (C++20)

countr_one (C++20)

popcount (C++20)

endian (C++20)

 

std::complex

成员函数
complex::complex
complex::operator=
complex::real
complex::imag
complex::operator+=complex::operator-=complex::operator*=complex::operator/=
非成员函数
operator+operator- operator+operator-operator*operator/ operator==operator!= operator<<operator>>	real imag abs arg norm conj proj (C++11) polar operator""ioperator""ifoperator""il (C++14)(C++14)(C++14)
指数函数
exp
log
log10
幂函数
pow
sqrt
三角函数
sin cos tan	asin (C++11) acos (C++11) atan (C++11)
双曲函数
sinh cosh tanh	asinh (C++11) acosh (C++11) atanh (C++11)

 

定义于头文件 <complex>
template< class T > complex<T> log10( const complex<T>& z );

计算复数值 z 的复常用（底 10 ）对数，分支切割沿负实轴。

此函数的行为等价于 std::log(z)/std::log(T(10)) 。

参数

z

-

复数值

返回值

z 的复常用对数

示例

运行此代码

#include <iostream>
#include <cmath>
#include <complex>
 
int main()
{
    std::complex<double> z(0, 1); // // r = 0, θ = pi/2
    std::cout << "2*log10" << z << " = " << 2.*std::log10(z) << '\n';
 
    std::complex<double> z2(sqrt(2)/2, sqrt(2)/2); // r = 1, θ = pi/4
    std::cout << "4*log10" << z2 << " = " << 4.*std::log10(z2) << '\n';
 
    std::complex<double> z3(-100, 0); // r = 100, θ = pi
    std::cout << "log10" << z3 << " = " << std::log10(z3) << '\n';
    std::complex<double> z4(-100, -0.0); // 切割的另一侧
    std::cout << "log10" << z4 << " (the other side of the cut) = "
              << std::log10(z4) << '\n'
              << "(note: pi/log(10) = " << acos(-1)/log(10) << ")\n";
}

输出：

2*log10(0,1) = (0,1.36438)
4*log10(0.707107,0.707107) = (0,1.36438)
log10(-100,0) = (2,1.36438)
log10(-100,-0) (the other side of the cut) = (2,-1.36438)
(note: pi/log(10) = 1.36438)

参阅

log(std::complex)	沿负实轴切割的复自然对数 (函数模板)
log10log10flog10l (C++11)(C++11)	计算常用（以 10 为底）对数（log10(x)） (函数)
log10(std::valarray)	应用函数 std::log10 到 valarray 的每个元素 (函数模板)