我想绘制一个数据,其中 x 轴
具有日期时间值,另一组值作为 y
。作为示例,我将使用 example来自 matplotlib,其中 y
在这种情况下是股票价格。这是相关代码。
import matplotlib.pyplot as plt
from matplotlib.finance import quotes_historical_yahoo_ochl
from matplotlib.dates import YearLocator, MonthLocator, DateFormatter
import datetime
date1 = datetime.date(1995, 1, 1)
date2 = datetime.date(2004, 4, 12)
years = YearLocator() # every year
months = MonthLocator() # every month
yearsFmt = DateFormatter('%Y')
quotes = quotes_historical_yahoo_ochl('INTC', date1, date2)
if len(quotes) == 0:
raise SystemExit
dates = [q[0] for q in quotes]
opens = [q[1] for q in quotes]
fig, ax = plt.subplots()
ax.plot_date(dates, opens, '-')
# format the ticks
ax.xaxis.set_major_locator(years)
ax.xaxis.set_major_formatter(yearsFmt)
ax.xaxis.set_minor_locator(months)
ax.autoscale_view()
# format the coords message box
def price(x):
return '$%1.2f' % x
ax.fmt_xdata = DateFormatter('%Y-%m-%d')
ax.fmt_ydata = price
ax.grid(True)
fig.autofmt_xdate()
plt.show()
现在,我想做的是根据某些标准为图表中的每个值着色。为简单起见,假设示例中的标准是基于年份的。也就是说,属于同一年的价格将使用相同的颜色。我该怎么做?谢谢!
最佳答案
您可以在您想要的范围内(在本例中为一年)使用带有掩码的 numpy 数组。为了使用示例中的内置 YearLocator
函数,您需要先绘制图形并设置刻度,然后从示例中删除并替换为每年的范围,
import matplotlib.pyplot as plt
from matplotlib.finance import quotes_historical_yahoo_ochl
from matplotlib.dates import YearLocator, MonthLocator, DateFormatter
import datetime
import numpy
date1 = datetime.date(1995, 1, 1)
date2 = datetime.date(2004, 4, 12)
years = YearLocator() # every year
months = MonthLocator() # every month
yearsFmt = DateFormatter('%Y')
quotes = quotes_historical_yahoo_ochl('INTC', date1, date2)
if len(quotes) == 0:
raise SystemExit
dates = np.array([q[0] for q in quotes])
opens = np.array([q[1] for q in quotes])
fig, ax = plt.subplots()
l = ax.plot_date(dates, opens, '-')
# format the ticks
ax.xaxis.set_major_locator(years)
ax.xaxis.set_major_formatter(yearsFmt)
ax.xaxis.set_minor_locator(months)
ax.autoscale_view()
l[0].remove()
py = years()[0]
for year in years()[1:]:
mask = (py < dates) & (dates < year)
ax.plot_date(dates[mask], opens[mask], '-')
py = year
# format the coords message box
def price(x):
return '$%1.2f' % x
ax.fmt_xdata = DateFormatter('%Y-%m-%d')
ax.fmt_ydata = price
ax.grid(True)
fig.autofmt_xdate()
plt.show()
这给出了,
关于Python Matplotlib : Changing color in plot_date,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40360979/