使用 Matplotlib 跳过 Python 中的某些值

Question

我目前正在使用 Alpha Vantage API 制作日内股票图表。数据框包含从 4:00 到 20:00 的值。然而，在我的 matplotlib.pyplot 图表中，x 轴还包括夜间 20:00 到 4:00 的值。我不想要这个，因为它扰乱了美学和 Volume 子图。

问：有什么方法可以跳过实际数据框中不存在的 x 轴值（从 20:00 到 04:00 的值）？

可以看到，Data Frame 明显从 20:00 跳到了 04:00

然而在 Matplotlib 图表中，x 轴包含从 20:00 到 4:00 的值，弄乱了图表

代码到此为止。我相信到目前为止一切都是正确的：

import pandas as pd

import matplotlib.pyplot as plt

from alpha_vantage.timeseries import TimeSeries

import time

import datetime as dt

from datetime import timedelta as td 

from dateutil.relativedelta import relativedelta

#Accessing and Preparing API

ts = TimeSeries(key=api_key, output_format='pandas')

ticker_input = "TSLA"

interval_input = "15min"

df, meta_data = ts.get_intraday(symbol = ticker_input, interval = interval_input, outputsize = 'full')

slice_date = 16*4*5

df = df[0:slice_date]

df = df.iloc[::-1]

df["100ma"] = df["4. close"].rolling(window = 50, min_periods = 0).mean()

df["Close"] = df["4. close"]

df["Date"] = df.index

#Plotting all as 2 different subplots

ax1 = plt.subplot2grid((7,1), (0,0), rowspan = 5, colspan = 1)

ax1.plot(df["Date"], df['Close'])

ax1.plot(df["Date"], df["100ma"], linewidth = 0.5)

plt.xticks(rotation=45)

ax2 = plt.subplot2grid((6,1), (5,0), rowspan = 2, colspan = 2, sharex = ax1)

ax2.bar(df["Date"], df["5. volume"])

ax2.axes.xaxis.set_visible(False)

plt.tight_layout()

plt.show()

如果有人可以提供帮助，那就太好了。我仍然是一个完全的初学者，两周前才开始使用 Python。

Answer 1

我们从同一个地方获取数据，尽管数据获取方法不同。在以 15 个单位提取后，我通过排除晚上 8 点之后和下午 4 点之前的数据创建了一个图表。我在理解您的跳过会打开暂停的情况下创建了代码。一旦设置了 NaN，您希望它跳过的内容就会被跳过。import datetimeimport pandas as pdimport numpy as npimport pandas_datareader.data as webimport mplfinance as mpf# import matplotlib.pyplot as pltwith open('./alpha_vantage_api_key.txt') as f:&nbsp; &nbsp; api_key = f.read()now_ = datetime.datetime.today()start = datetime.datetime(2019, 1, 1)end = datetime.datetime(now_.year, now_.month, now_.day - 1)symbol = 'TSLA'df = web.DataReader(symbol, 'av-intraday', start, end, api_key=api_key)df.columns = ['Open', 'High', 'Low', 'Close', 'Volume']df.index = pd.to_datetime(df.index)df["100ma"] = df["Close"].rolling(window = 50, min_periods = 0).mean()df["Date"] = df.indexdf_15 = df.asfreq('15min')df_15 = df_15[(df_15.index.hour >= 4)&(df_15.index.hour <= 20) ]import matplotlib.pyplot as pltfig = plt.figure(figsize=(8,4.5),dpi=144)#Plotting all as 2 different subplotsax1 = plt.subplot2grid((7,1), (0,0), rowspan = 5, colspan = 1)ax1.plot(df_15["Date"], df_15['Close'])ax1.plot(df_15["Date"], df_15["100ma"], linewidth = 0.5)plt.xticks(rotation=20)ax2 = plt.subplot2grid((6,1), (5,0), rowspan = 2, colspan = 2, sharex = ax1)ax2.bar(df_15["Date"], df_15["Volume"])ax2.axes.xaxis.set_visible(False)# plt.tight_layout()plt.show()

Answer 2

我使用 matplotlib.ticker.formatter 修复了它。我首先创建了一个类并使用：class MyFormatter(Formatter):&nbsp; &nbsp; def __init__(self, dates, fmt='%Y-%m-%d %H:%M'):&nbsp; &nbsp; &nbsp; &nbsp; self.dates = dates&nbsp; &nbsp; &nbsp; &nbsp; self.fmt = fmt&nbsp; &nbsp; def __call__(self, x, pos=0):&nbsp; &nbsp; &nbsp; &nbsp; 'Return the label for time x at position pos'&nbsp; &nbsp; &nbsp; &nbsp; ind = int(np.round(x))&nbsp; &nbsp; if ind >= len(self.dates) or ind < 0:&nbsp; &nbsp; &nbsp; &nbsp; return ''&nbsp; &nbsp; return self.dates[ind].strftime(self.fmt)formatter = MyFormatter(df.index)ax1 = plt.subplot2grid((7,1), (0,0), rowspan = 5, colspan = 1)ax1.xaxis.set_major_formatter(formatter)ax1.plot(np.arange(len(df)), df["Close"])ax1.plot(np.arange(len(df)), df["100ma"], linewidth = 0.5)ax1.xticks(rotation=45)ax1.axis([xmin,xmax,ymin,ymax])ax2 = plt.subplot2grid((6,1), (5,0), rowspan = 2, colspan = 2, sharex = ax1)ax2.bar(np.arange(len(df)), df["5. volume"])plt.show()这给了我一个比之前更平滑的图表，也是 r-beginner 推荐的图表。我遇到的唯一问题是，如果我放大 x 轴并没有真正改变。它总是有年、月、日、小时和分钟。显然，当我进一步放大时，我只想要小时和分钟。我还没有弄清楚该怎么做