我的cosh与他们的cosh

本文介绍了我的cosh与他们的cosh的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 GeoGrebra，C ++和C＃都同意cosh（16.612）应该是什么。但是当我使用我自己编写的函数时，它使用算法计算双曲余弦，我得到（非常轻微）不同的结果。我已经尝试将Visual Studio的浮点处理设置为精确，严格和快速，但无济于事。 问题可能是什么？ 这是其他人都同意的： Hi,GeoGrebra, C++ and C# all agree about what cosh(16.612) should be. But when I use a function I wrote myself, which uses an algorithm to calculate the hyperbolic cosine, I get a (very slightly) different result. I've tried setting Visual Studio's floating point handling to precise, strict and fast, but to no avail.What could the proble be?This is the one that everyone else agrees about: cosh(16.612000) = 8193509.0494933873414993 这是我的第一种方法： This is my first approach: _cosh(16.612000) = 8193509.0494933854788542 我的第二种： And my second: ecosh(16.612000) = 8193509.0494933798909187 最后一个使用cosh（x）= 0.5（e ^ x + e ^（ - x）） 这是我的代码： The last one uses cosh(x) = 0.5(e^x + e^(-x))Here is my code:#include <cstdio>#include <iostream>#include <string>long double e = 2.718281828459045090795598298427648842334747314453125L;long double ecosh(long double x) {//return 0.5 * (exp(x) + exp(-x));return 0.5L * (pow(e, x) + pow(e, -x));}using namespace std;using decimal = double;constexpr bool b(int i) { return i > 0; }static_assert(b(7), "hej");auto f = [=](double x) {return sqrt(x*x*x);};long double fac(long double x) {if ((int)x > 1)return x * fac(x - 1);return 1;}//25/2 + 25/4 - 25/2/2*1.5 + 25/2/2/2*1.5decimal _sqrt(decimal x, int iterations = 15) {decimal y = x - x / 2 + x / 4;for (int i = 1; i < 49; i++) {y += x / pow(2, i) * 1.5 * pow(-1, i);}return y+0.0000000001;}long double _cosh2(double x) {long double y = 0;for (int i = 1; i < 70; i++) {y += pow(x, (double)(2.0*i)) / fac(2.0*i);}return y+1;}long double _sinh2(double x) {long double y = x;for (int i = 1; i < 70; i++) {y += pow(x, (double)(2.0*i+1)) / fac(2.0*i+1);}return y + 0;}int main(int argc, char** argv){double r = 4.0;printf("sqrt(%f) = %.25f\n\n", r, _sqrt(r));printf("sqrt(%f) = %.25f\n\n", r, sqrt(r));double d = 16.612;printf("_cosh(%f) = %.16f\n cosh(%f) = %.16f\n", d, _cosh2(d), d, cosh(d));printf("ecosh(%f) = %.16lf\n", d, ecosh(d));printf("--------------------------------------\n");printf("e() = %.75lf\ne = %.75f\n", exp(1.0L), e);printf(" %.50f\n", _sinh2(6.125));printf(" %.50f\n", sinh(6.125));getchar();} 我的尝试： 我尝试重新配置Visual Studio 2017. What I have tried:I've tried reconfiguring Visual Studio 2017.推荐答案 decimal y = x - x / 2. + x / 4.;以避免舍入问题。 这篇关于我的cosh与他们的cosh的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！