Question

我在使用割线方法

运行c ++代码以查找自定义方程的根时遇到问题

我在声明变量方面遇到了问题。它显示错误

错误：＆＃39; p＆＃39;在这方面没有申明 if（f（x1，c，p，pr）* f（x2，c，p，pr）＆lt; 0）{ ^ 和

错误：＆＃39; pr＆＃39;在这方面没有申明 ^

 #include <iostream>

  using namespace std;


#include <iostream>

// C++ Program to find root of an 
// equations using secant method
#include <bits/stdc++.h>
using namespace std;
// function takes value of x and returns f(x)
float f(float x, float c, float p, float pr)
  {

    float f = pow((c/2)/(1 + x/2),p) + pow((c/2)/(1 + x/2),(p-1)) + pow(100/(1 + x/2),p) - pr;
    return f;
  }

 void secant(float x1, float x2, float E)
  {

    float n = 0, xm, x0, c;
    if (f(x1,c,p,pr) * f(x2,c,p,pr) < 0) {
      do {
        // calculate the intermediate value
        x0 = (x1 * f(x2,c,p,pr) - x2 * f(x1,c,p,pr)) / (f(x2,c,p,pr) - f(x1,c,p,pr));

        // check if x0 is root of equation or not 
        c = f(x1,c,p,pr) * f(x0,c,p,pr);

        // update the value of interval
        x1 = x2;
        x2 = x0;

        // update number of iteration
        n++;

        // if x0 is the root of equation then break the loop
        if (c == 0)
          break;
        xm = (x1 * f(x2,c,p,pr) - x2 * f(x1,c,p,pr)) / (f(x2,c,p,pr) - f(x1,c,p,pr));
      } while (fabs(xm - x0) >= E); // repeat the loop
      // until the convergence

      cout << "Root of the given equation=" << x0 << endl;
      cout << "No. of iterations = " << n << endl;
    } else
      cout << "Can not find a root in the given inteval";
  }

// Driver code
int main()
{
  float c ;
  float p ;
  float pr ;
  cout << "Please enter the coupon" << endl ;
  cin >> c ;
  cout  << "Please enter the period" << endl ;
  cin >> p ;
  cout << "Please enter the dirty price" <<endl ;
  cin >> pr; 
  float x1 = 0, x2 = 15, E = 0.0001;

    // initializing the values

  secant(x1, x2, E);
  return 0;
}

Answer 1

您可以将变量传递给函数，将这些参数添加到函数

void secant(float x1, float x2, float E,float c,flaot p,float pr)

并像这样调用函数

secant(x1, x2, E,c,p,pr);

错误：＆＃39; p＆＃39;在这方面没有申明

1 个答案: