对于我的图,我想在散景中使用“日期时间”选项,如下所示:
top = figure(width=900, height=500, x_axis_type='datetime')
我的 x 轴数据采用 datetime.time 格式。
x_time = [datetime.time(0, 0), datetime.time(0, 0, 3), datetime.time(0, 0, 13), datetime.time(0, 0, 23), datetime.time(0, 0, 26)]
但是在尝试添加时会产生以下错误:
top.image_url(x=datetime.time(0,0,3), y= 10 url = [some_url]]
和
top.add_layout(Arrow(x_start=datetime.time(0,0,0), y_start=5,
x_end=datetime.time(0,0,3), y_end=10)
ValueError: expected an element of either String, Dict(String, Either(String, Instance(Transform), Instance(ColorMapper), Float)) or Float, got datetime.time(0, 0)
至少从 bokeh 0.12.5 开始,如果您的 x 轴包含日期时间格式的数据,您可以简单地将其声明为figure函数中的参数,并且将为您完成格式化:
plot=figure(plot_height=300, plot_width=800,x_axis_type="datetime")
Bokeh 注释似乎只接受数字,而不是
Datetime
或 Time
对象。解决方法是将您的时间转换为微秒并使用它们来绘图。
一个例子:
from bokeh.plotting import figure, show, output_notebook
from bokeh.models import Arrow
import datetime
def time_to_microseconds(t):
dmin = datetime.datetime.min
dummy_tdelta = (datetime.datetime.combine(dmin, t) - dmin)
return dummy_tdelta.total_seconds()*1000
x_time = [datetime.time(0,0,1),
datetime.time(0,0,2),
datetime.time(0,0,3),
datetime.time(0,0,4),
datetime.time(0,0,5)]
top = figure(width=300, height=300, x_axis_type='datetime')
# a line works fine with time objects
top.line(x_time, range(len(x_time)))
# layout needs numbers
top.add_layout(Arrow(x_start=time_to_microseconds(datetime.time(0,0,2)),
y_start=3,
x_end=time_to_microseconds(datetime.time(0,0,3)),
y_end=2))
编辑:
您可以使用以下方法更改刻度格式:
from bokeh.models import DatetimeTickFormatter
top.xaxis.formatter = DatetimeTickFormatter(seconds=["%M:%S"],
minutes=["%M:%S"],
minsec=["%M:%S"],
hours=["%M:%S"])