#/***********************************************************
#    corrcoef.c -- 相関係数
#***********************************************************/
#include <stdio.h>
#include <math.h>

def corrcoef1( n,  x,  y)




    sx = sy = sxx = syy = sxy = 0
    for i in 0...n
        sx += x[i];  sy += y[i]
    end
    sx /= n;  sy /= n
    for i in 0...n
        dx = x[i] - sx;  dy = y[i] - sy
        sxx += dx * dx;  syy += dy * dy;  sxy += dx * dy
    end
    sxx = Math::sqrt(sxx / (n - 1))
    syy = Math::sqrt(syy / (n - 1))
    sxy /= (n - 1) * sxx * syy
    printf("標準偏差 %g %g  相関係数 %g\n", sxx, syy, sxy)
end

def corrcoef2( n,  x,  y)




    sx = sy = sxx = syy = sxy = 0
    for i in 0...n
        sx += x[i];  sy += y[i]
        sxx += x[i] * x[i]
        syy += y[i] * y[i]
        sxy += x[i] * y[i]
    end
    sx /= n;  sxx = (sxx - n * sx * sx) / (n - 1)
    sy /= n;  syy = (syy - n * sy * sy) / (n - 1)
    if (sxx > 0) sxx = Math::sqrt(sxx);  else sxx = 0
    if (syy > 0) syy = Math::sqrt(syy);  else syy = 0
    sxy = (sxy - n * sx * sy) / ((n - 1) * sxx * syy)
    printf("標準偏差 %g %g  相関係数 %g\n", sxx, syy, sxy)
end

def corrcoef3( n,  x,  y)




    sx = sy = sxx = syy = sxy = 0
    for i in 0...n
        dx = x[i] - sx;  sx += dx / (i + 1)
        dy = y[i] - sy;  sy += dy / (i + 1)
        sxx += i * dx * dx / (i + 1)
        syy += i * dy * dy / (i + 1)
        sxy += i * dx * dy / (i + 1)
    end
    sxx = Math::sqrt(sxx / (n - 1))
    syy = Math::sqrt(syy / (n - 1))
    sxy /= (n - 1) * sxx * syy
    printf("標準偏差 %g %g  相関係数 %g\n", sxx, syy, sxy)
end

#include <stdlib.h>
#include "statutil.c"
NMAX = 1000

begin



    static  x[NMAX], y[NMAX]

    n = 0
    while (true) 
        t = getnum(stdin);  u = getnum(stdin)
        if (readerror(t) || readerror(u)) break
        if (missing(t) || missing(u)) continue
        if (n >= NMAX) error("多すぎます")
        x[n] = t;  y[n] = u;  n += 1
    end
    printf("データの件数 %d\n", n)
    corrcoef1(n, x, y)
    corrcoef2(n, x, y)
    corrcoef3(n, x, y)
    return EXIT_SUCCESS
end