std::log10(std::complex)
定义于头文件 <complex>
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template< class T > complex<T> log10( const complex<T>& z ); |
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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
沿负实轴切割的复自然对数 (函数模板) | |
(C++11)(C++11) |
计算常用(以 10 为底)对数( log10(x) ) (函数) |
应用函数 std::log10 到 valarray 的每个元素 (函数模板) |