我正在使用三个独立的数据框绘制散点图,并绘制点以及最佳拟合线。我可以使用以下代码完成此操作:
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
fig=plt.figure()
ax1=fig.add_subplot(111)
ax2=fig.add_subplot(111)
ax3=fig.add_subplot(111)
#create scatter plots from the dataframes
ax1.scatter(ex_x, ex_y, s=10, c='r', label='Fire Exclusion')
ax2.scatter(one_x,one_y, c='b', marker='s',label='One Fire')
ax3.scatter(two_x, two_y, s=10, c='g', marker='^', label='Two Fires')
#plot lines of best fit
ax1.plot(ex_x,ex_results.predict(), color = 'r',label = 'Linear (Fire Exclusion)')
ax2.plot(one_x,one_results.predict(), color = 'b',label = 'Linear (One Fire)')
ax3.plot(two_x,two_results.predict(), color = 'g',label = 'Linear (Two Fires)')
#add legend and axis labels
plt.xlabel('NDVI 2004/07/27')
plt.ylabel('NDVI 2005/07/14')
plt.title('NDVI in 2004 vs. 2005')
plt.legend(loc='center left', bbox_to_anchor=(1, 0.5), scatterpoints=1)
给了我:
现在我想添加第二个图例,它将显示每行的r2。我试图这样做:
fig=plt.figure()
ax1=fig.add_subplot(111)
ax2=fig.add_subplot(111)
ax3=fig.add_subplot(111)
scat1,=ax1.scatter(ex_x, ex_y, s=10, c='r', label='Fire Exclusion')
scat2,=ax2.scatter(one_x,one_y, c='b', marker='s',label='One Fire')
scat3,=ax3.scatter(two_x, two_y, s=10, c='g', marker='^', label='Two Fires')
lin1,=ax1.plot(ex_x,ex_results.predict(), color = 'r',label = 'Linear (Fire Exclusion)')
lin2,=ax2.plot(one_x,one_results.predict(), color = 'b',label = 'Linear (One Fire)')
lin3,=ax3.plot(two_x,two_results.predict(), color = 'g',label = 'Linear (Two Fires)')
l1 = plt.legend([scat1, scat2,scat3,lin1,lin2,lin3], ["Fire Exclusion", "One Fire", "Two Fires", "Linear (Fire Exclusion)", "Linear (One Fire)", "Linear (Two Fires)"], loc='upper left', scatterpoints=1)
#get r2 from regression results
r2ex=ex_results.rsquared
r2one=one_results.rsquared
r2two=two_results.rsquared
plt.legend([r2ex, r2one, r2two], ['R2 (Fire Exclusion)', 'R2 (One Fire)', 'R2 (Two Fires)'], loc='lower right')
plt.gca().add_artist(l1)
plt.xlabel('NDVI 2004/07/27')
plt.ylabel('NDVI 2005/07/14')
plt.title('NDVI in 2004 vs. 2005')
但这会返回:
Traceback (most recent call last):
File "<ipython-input-32-b6277bf27ded>", line 1, in <module>
runfile('E:/prelim_codes/Fire.py', wdir='E:/prelim_codes')
File "C:\Users\Stefano\Anaconda2_2\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 714, in runfile
execfile(filename, namespace)
File "C:\Users\Stefano\Anaconda2_2\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 74, in execfile
exec(compile(scripttext, filename, 'exec'), glob, loc)
File "E:/prelim_codes/Fire.py", line 539, in <module>
scat1,=ax1.scatter(ex_x, ex_y, s=10, c='r', label='Fire Exclusion')
TypeError: 'PathCollection' object is not iterable
答案 0 :(得分:9)
我有同样的错误。我发现你不应该在你的变量名后包含逗号。所以试试
scat1 =ax1.scatter(ex_x, ex_y, s=10, c='r', label='Fire Exclusion')
scat2 =ax2.scatter(one_x,one_y, c='b', marker='s',label='One Fire')
scat3 =ax3.scatter(two_x, two_y, s=10, c='g', marker='^', label='Two Fires')
而不是
scat1,=ax1.scatter(ex_x, ex_y, s=10, c='r', label='Fire Exclusion')
scat2,=ax2.scatter(one_x,one_y, c='b', marker='s',label='One Fire')
scat3,=ax3.scatter(two_x, two_y, s=10, c='g', marker='^', label='Two Fires')
这是因为axes.scatter返回一个PathCollection,而不像axes.plot,它返回所绘制的行的元组(参见http://matplotlib.org/1.3.1/users/pyplot_tutorial.html#controlling-line-properties和Python code. Is it comma operator?)。
因此,对于你的行,你仍然需要逗号,因为你正在解包元组,但是对于散布你不应该有逗号。