#/***********************************************************
#    corrcoef.rb -- 相関係数
#***********************************************************/

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 = Math::sqrt(sxx); end
    if (syy > 0); syy = Math::sqrt(syy); else; syy = Math::sqrt(syy); end
    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

require "statutil.rb"
NMAX = 1000

x = []; y = []

n = 0

while (true) 
    t = getnum($stdin); u = getnum($stdin);
    if (readerror(t) || readerror(u)); break; end
    if (missing(t) || missing(u)); next; end
    if (n >= NMAX); error("多すぎます"); end
    x[n] = t.to_f;  y[n] = u.to_f; 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)

exit 0