問題與割線根發現C++

Question

我正在試圖爲學校將使用割線根發現方法的程序。的公式爲：

（V/B）^ 2sin（阿爾法）= KR * TS^4個+ UC * TS -q

，我必須找到TS。

不幸的是，我一直用作我的基地的例子並不適合我：。它給出的根是-1.QNAN或者沿着這些行的東西，所以我在某種地方在割線方法中出現錯誤，我是C++的新手，所以我在解決這個問題時遇到了很多麻煩。任何幫助將不勝感激，如果有人可以告訴我的代碼，以便更容易發佈代碼，我將不勝感激。謝謝 這裏是我的代碼到目前爲止：

#include <iostream> 
#include <cmath> 
#include <fstream> 
#include <iomanip> 

using namespace std; 

void secant (double, double, double, double, double, double, double, double, double, double, double, int); 

double fx(double, double, double, double, double, double, double); 

const double tol=0.0001; // Tolerance for convergence 

const int max_iter=50;  // Maximum iterations allowed 

int main() 
{ 
    double kr, uc, q, b, radians, Ts, x0, x1, root; 
    int iteration; 
    const double PI = 4.0*atan(1.0); 

    ifstream datain ("shuttle.txt"); 
    ofstream dataout ("results.txt"); 

    datain >> kr >> uc >> q >> b; 

    int velocity = 16000; 
    double angle =10; 

    x0= 1000; 
    x1 = 200; 

    for (int velocity = 16000; velocity <= 17500; velocity += 500) { 
     for (int angle = 10; angle <= 70; angle += 15) { 
      radians= angle * PI/180 ; 

      cout << velocity << endl; 
      cout << radians << endl; 
      cout << angle << endl; 

      secant (angle, radians, velocity, kr, uc, q, b, Ts, x0, x1, root, iteration);  
     } 
    } 
    system("pause"); 

    return 0; 
} 

void secant(double angle, double radians, double velocity, double kr, double uc, double q, double b, double Ts, double x0, double x1, double root, int iteration) 
{ 
    double xnminus1, xnplus1, xn; 
    iteration=0; 
    xnminus1=x0; 
    xn=x1; 

    do 
    { 
     ++iteration; 
     xnplus1 = xn - fx(kr, uc, Ts, q, velocity, radians, xn)*(xn-xnminus1)/ 
        (fx(kr, uc, Ts, q, velocity, radians,xn)-fx(kr, uc, Ts, q, velocity, radians,xnminus1)); 

     cout<<"x"<<iteration+1<<" = "<<xnplus1<<endl; 

     xnminus1 = xn; 

     xn=xnplus1; 

    } 

    while ((fabs(fx(kr, uc, Ts, q, velocity, radians, xnplus1)) >= tol)&& (iteration < max_iter)) 
     ;  
    root=xnplus1; 

    cout<<"\nThe root is = "<<root<<endl; 
    cout<<"The number of iterations was = "<<iteration<<endl; 
    cout<<"The value of f(x) at the root = "<<fx(kr, uc, Ts, q, velocity, radians, root) <<endl<<endl;  
} 

double fx(double kr, double uc, double Ts, double q, double velocity, double b, double radians) 
{ 
    return kr * pow(Ts, 4.0) + uc * Ts - q - pow(velocity/b, 2.0) * sin(radians); 
} 

Answer 1

你使用Ts而沒有定義它。有趣的是，它以藍色突出顯示...我認爲有一位高級SO用戶在某處笑了...