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数字 | Numerics

std::log10(std::complex)

STD::log 10%28 std::Complex%29

Defined in header
template< class T > complex<T> log10( const complex<T>& z

计算复杂的公共%28碱基10复值的%29对数z在负实轴上有一个分支。

此函数的行为等价于std::log(z)/std::log(10)...

参数

z-complex value

返回值

复公对数z...

二次

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

二次

产出:

二次

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)

二次

另见

log(std::complex)complex natural logarithm with the branch cuts along the negative real axis (function template)
log10computes common (base 10) logarithm (log10(x)) (function)
log10(std::valarray)applies the function std::log10 to each element of valarray (function template)

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