C ++标准差

Question

#include <stdio.h>      /* printf, scanf, puts, NULL */
#include <iostream>     /* cin and cout functions */
#include <cmath>        /*for power function etc.. */
#include <string>       /*to let us use strings as inputs */
#include <sstream>      /*allows conversion of strings to floats */
#include <fstream>      /*has all the file input functions */
#include <cmath>
using namespace std;    /*saves some typing*/

int main()
{
    string Myline;  //this will contain the data read from the file
    ifstream myfile("StatNum2.txt");    //associate file with the input stream, note file must be in project directory with cpp file.
                                    //need to put in correct filename in place of Filename.***



    int n = 0;
    float numPoints = 0.0;
    int Points[200];


    // Normal comment
    /* Multi-line comment */

    if (myfile.is_open())
    {
        cout << "File is open" << endl;
        while (!myfile.eof())   //note the ! this means this loops reads through until the file closes
        {
            getline(myfile, Myline);    //this reads a single line from myfile into Myline
            stringstream convert(Myline);

            if (!(convert >> Points[n]))    //uses stringstream to convert Myline (which is a string) into a number and put it into an index of Points
            {
                Points[n] = 0;
            }

            cout << n;
            cout << ' ';
            cout << Points[n] << endl;
            n++;
        }
        myfile.close();
        numPoints = n;
        cout << "Number of integers: " << numPoints << endl;
    }
    else
    {
        cout << "Could not open file" << endl;
    }

    int sum = 0.0;
    for (int i = 0; i < numPoints; i = i + 1)
    {
        // Code here will be repeated as long as 'i' is less than 100.
        sum = sum + Points[i];
    }

    cout << "Sum: " << sum << endl;

    float average = sum / numPoints;
    cout << "Average: " << average << endl;

    int x = 0;
    float sqdiff = 0.0;
    for (int x = 0; x < numPoints; x = x + 1);
    {
        sqdiff = (Points[x] - average)*(Points[x] - average);
    }
    cout << "difference of squares:" << sqdiff << endl;

    float stddev = sqrt(sqdiff/n);
    cout << "Standard Deviation:" << stddev << endl;

我正在尝试找到标准偏差但是从第65行上面的代码遇到了一些问题。代码产生了错误的结果或说Point [x]未定义，因此不确定如何修复

任何帮助将不胜感激，谢谢