学习笔记----python绘图loglog

# python 绘制双对数坐标曲线图并进行线性拟合

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import numpy as np

import pandas as pd

import matplotlib.pyplot as plt

from scipy import optimize

# read the data

data = pd.read_excel("input.xlsx")

x = data['Offset']

y = data['Amplitude']

# fit function

def f(X, A, B):

    return A*X+B

A,B = optimize.curve_fit(f, x, y)[0]

print(A)

print(B)

xx = np.arange(47, 28010, 10)

yy = A*xx+B

ss = 'y=' + str(A) + '*' + 'x' + '+' + str(B)

# draw picture

plt.scatter(x,y,s=100)

plt.loglog(x,y,label='raw data',linestyle='--',color='r',linewidth=2)

plt.plot(xx,yy,label='linear fitting',color='g',linewidth=2)

plt.title(ss,fontsize=14)

plt.xlabel("offset",fontsize=14)

plt.ylabel("Amplitude",fontsize=14)

plt.tick_params(axis='both',labelsize=10)

plt.legend(loc='best')

plt.show()