如何将 x 轴设置为散景图上的日期时间？

Question

I'm using bokeh with an ipython notebook.

I want to plot a line graph in bokeh using a pandas DataFrame containing datetimes:

import pandas as pd
from datetime import datetime as dt
from bokeh.io import output_notebook
from bokeh.charts import Bar, Line, show

df = pd.DataFrame(data=[1,2,3],
                  index=[dt(2015, 1, 1), dt(2015, 1, 2), dt(2015, 1, 3)],
                  columns=['foo'])

output_notebook()
show(Line(df))

However, bokeh uses microseconds! Why is this? How do I fix it?

Answer 1

从散景 0.12.3 开始，您现在可以执行以下操作：

p = figure(..., x_axis_type='datetime', ...)

Answer 2

is that ok ?

import pandas as pd
from math import pi
from datetime import datetime as dt
from bokeh.io import output_file
from bokeh.charts import show
from bokeh.models import DatetimeTickFormatter
from bokeh.plotting import figure

df = pd.DataFrame(data=[1,2,3],
                  index=[dt(2015, 1, 1), dt(2015, 1, 2), dt(2015, 1, 3)],
                  columns=['foo'])
p = figure(plot_width=400, plot_height=400)
p.line(df.index, df['foo'])
p.xaxis.formatter=DatetimeTickFormatter(
        hours=["%d %B %Y"],
        days=["%d %B %Y"],
        months=["%d %B %Y"],
        years=["%d %B %Y"],
    )
p.xaxis.major_label_orientation = pi/4
output_file('myplot.html')
show(p)

Answer 3

FWIW, the default behavior has changed since the question was first posted. The original code now yields: