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step1執行。我做一堆點的線性迴歸並得到一條線。 step2。我通過平均這一堆點 step3得到一箇中心點。我想在步驟1中找到垂直於迴歸線的直線並穿過步驟2中提到的中心點。確定一條垂直於另一條線的線，該線由python
了我認爲：假設迴歸線Y1 = K1 * X1 + B1，垂直線Y2 = K2 * X2 + B2，然後，K2 = -1/K1
問題：從該圖，看起來像兩條直線不垂直。爲什麼？發生了什麼事
我的Python代碼：`
import numpy as np
import scipy.linalg
import matplotlib.pyplot as plt
from openpyxl import load_workbook
x = [140.0, 139.0, 145.0, 151.0, 156.0, 160.0, 162.0, 162.0, 156.0, 139.0, 129.0, 124.0, 125.0, 128.0, 127.0, 126.0, 126.0, 132.0, 139.0, 145.0, 150.0, 156.0, 155.0, 148.0, 135.0, 129.0, 125.0, 127.0, 128.0, 126.0, 123.0, 124.0, 130.0, 135.0, 142.0, 151.0, 158.0, 155.0, 148.0, 140.0, 126.0, 124.0, 127.0, 127.0, 126.0, 126.0, 126.0, 131.0, 138.0, 141.0, 159.0, 167.0, 162.0, 155.0, 147.0, 141.0, 138.0, 140.0, 140.0, 140.0, 138.0, 143.0, 150.0, 155.0, 163.0, 173.0, 178.0, 173.0]
y = [621.0, 621.0, 630.0, 638.0, 636.0, 635.0, 635.0, 634.0, 628.0, 623.0, 617.0, 614.0, 618.0, 622.0, 617.0, 610.0, 612.0, 622.0, 626.0, 623.0, 622.0, 624.0, 625.0, 618.0, 613.0, 607.0, 608.0, 614.0, 614.0, 608.0, 603.0, 612.0, 616.0, 617.0, 616.0, 618.0, 622.0, 622.0, 615.0, 609.0, 607.0, 610.0, 612.0, 607.0, 606.0, 601.0, 611.0, 617.0, 615.0, 614.0, 619.0, 624.0, 625.0, 619.0, 615.0, 613.0, 618.0, 622.0, 616.0, 610.0, 614.0, 628.0, 625.0, 624.0, 628.0, 638.0, 646.0, 645.0]
def get_center(x,y):
x = x[:-1]
y = y[:-1]
x0 = np.mean(x)
y0 = np.mean(y)
return x0, y0
#center point
x0,y0 = get_center(x,y)
#linear regression
# fit_fn is now a function which takes in x and returns an estimate for y
fit = np.polyfit(x,y,1)
fit_fn = np.poly1d(fit)
plt.plot(x0,y0,'bo')
#get the linear regression line
plt.plot(x,y, 'ro', x, fit_fn(x), '--k')
#get the perpendicular line going through the center point
plt.plot(x,(-1.0/fit[0])*(x-x0)+y0,'--b')
plt.grid(True)
plt.show()
this is the link of the graph I got by running the program
`
您的比例因x和y尺寸而異，所以線條失真。 – karakfa
謝謝，那就是 – Xuyong