Python散点图和matplotlib
问题描述:
我有一个散点图,我想绘制一个趋势线的python。从各种例子我已经在互联网发现学习如何绘制趋势线我的代码如下:Python散点图和matplotlib
import matplotlib.pyplot as plt
import numpy as np
x=np.array([9.80,13.20,13.46,14.09,13.96,10.77,8.79,8.61,8.83,11.08,10.13,12.40,9.90,10.96,12.75,11.79,11.79,12.38,12.78,13.08,12.83,12.57,12.96,12.90,12.91,13.67,12.83,12.50,12.42,12.83,12.82,12.70,12.60,12.90,13.20])
y=np.array([0.0706,0.0969,0.0997,0.1031,0.0848,0.1044,0.0815,0.1030,0.0783,0.0970,0.1193,0.0796,0.0697,0.0738,0.0895,0.0912,0.0887,0.0973,0.0942,0.1052,0.0984,0.0965,0.0903,0.0876,0.1071,0.0872,0.0857,0.0967,0.0926,0.0837,0.0967,0.0935,0.0946,0.0930,0.0758
])
plt.scatter(x, y)
fit = np.polyfit(x, y, deg=4)
p = np.poly1d(fit)
plt.plot(x,p(x),"r--")
plt.show()
但结果行,而不是作为一个曲线仅仅是一个线的组合。任何人都可以解释我的错误吗?
答
我认为这是因为x
值没有排序。看看这个代码:
import matplotlib.pyplot as plt
import numpy as np
x=np.array([9.80,13.20,13.46,14.09,13.96,10.77,8.79,8.61,8.83,11.08,10.13,12.40,9.90,10.96,12.75,11.79,11.79,12.38,12.78,
13.08,12.83,12.57,12.96,12.90,12.91,13.67,12.83,12.50,12.42,12.83,12.82,12.70,12.60,12.90,13.20])
y=np.array([0.0706,0.0969,0.0997,0.1031,0.0848,0.1044,0.0815,0.1030,0.0783,0.0970,0.1193,0.0796,0.0697,0.0738,
0.0895,0.0912,0.0887,0.0973,0.0942,0.1052,0.0984,0.0965,0.0903,0.0876,0.1071,0.0872,0.0857,0.0967,0.0926,0.0837,0.0967,0.0935,0.0946,0.0930,0.0758 ])
# Here I sort x values and their corresponding y values
args = np.argsort(x)
x = x[args]
y = y[args]
plt.scatter(x, y)
fit = np.polyfit(x, y, deg=4)
p = np.poly1d(fit)
plt.plot(x,p(x),"r--")
plt.show()
结果:
真的非常感谢你!我发现我有很长的路要学习...... – pma