Numpy-Arrays mit gleicher Form, aber mit ValueError: x und y müssen dieselbe erste Dimension haben

Question

Stumped. sie sind beide Numpy Arrays sie beide die gleiche Form sind also warum bin ich immer „Valueerror: x und y müssen gleiche erste Dimension haben“

dank

import matplotlib.pyplot as plt 
import numpy as np 
from datetime import datetime 

num_of_days = 31 
dates = np.empty(num_of_days) 
ranks = np.empty(dates.shape[0]) 
ranks.fill(50) # test data all 50's 
dates = np.arange('2016-01', num_of_days , dtype='datetime64[D]') 
print("ranks shape", ranks.shape) 
print("dates shape", dates.shape) 
print("ranks type", type(ranks)) 
print("dates type", type(dates)) 
print("dates shape first dimension",dates.shape[0]) 
print(dates) 
print(ranks) 

plt.plot_date(dates,2) 
plt.plot(dates,ranks) 
plt.show() 

Der Code Lauf Ausbeuten

Python 3.5.1 (v3.5.1:37a07cee5969, Dec 6 2015, 01:38:48) [MSC v.1900 32 bit (Intel)] on win32 
Type "copyright", "credits" or "license()" for more information. 
>>> 
===== RESTART: E:\scanned\als course\12 15 14 the al project\dev code\8 29 16 test plots.py ===== 
ranks shape (31,) 
dates shape (31,) 
ranks type <class 'numpy.ndarray'> 
dates type <class 'numpy.ndarray'> 
dates shape first dimension 31 
['2016-01-01' '2016-01-02' '2016-01-03' '2016-01-04' '2016-01-05' 
'2016-01-06' '2016-01-07' '2016-01-08' '2016-01-09' '2016-01-10' 
'2016-01-11' '2016-01-12' '2016-01-13' '2016-01-14' '2016-01-15' 
'2016-01-16' '2016-01-17' '2016-01-18' '2016-01-19' '2016-01-20' 
'2016-01-21' '2016-01-22' '2016-01-23' '2016-01-24' '2016-01-25' 
'2016-01-26' '2016-01-27' '2016-01-28' '2016-01-29' '2016-01-30' 
'2016-01-31'] 
[ 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 
    50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 50. 
    50.] 
Traceback (most recent call last): 
    File "E:\scanned\als course\12 15 14 the al project\dev code\8 29 16 test plots.py", line 23, in <module> 
    plt.plot_date(dates,2) 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\pyplot.py", line 3173, in plot_date 
    data=data, **kwargs) 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\__init__.py", line 1812, in inner 
    return func(ax, *args, **kwargs) 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\axes\_axes.py", line 1494, in plot_date 
    ret = self.plot(x, y, fmt, **kwargs) 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\__init__.py", line 1812, in inner 
    return func(ax, *args, **kwargs) 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\axes\_axes.py", line 1424, in plot 
    for line in self._get_lines(*args, **kwargs): 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\axes\_base.py", line 386, in _grab_next_args 
    for seg in self._plot_args(remaining, kwargs): 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\axes\_base.py", line 364, in _plot_args 
    x, y = self._xy_from_xy(x, y) 
    File "C:\Users\dave\AppData\Local\Programs\Python\Python35-32\lib\site-packages\matplotlib\axes\_base.py", line 223, in _xy_from_xy 
    raise ValueError("x and y must have same first dimension") 
ValueError: x and y must have same first dimension 
>>> 

Answer 1

Aus der Dokumentation:

plot_date(x, y, fmt='bo', tz=None, xdate=True, 
      ydate=False, **kwargs) 
Similar to the plot() command, except the x or y (or both) data is considered to be dates, and the axis is labeled accordingly. 

Ihre dates ist (31,), aber was ist mit der 2? Warum ist es nicht ein Array mit 31 Werten?

zeichnet eine Reihe von Punkten in einer steigenden Linie mit Daten auf der X-Achse.