Python,Bokeh：如何更改日期时间轴的范围

我想使用按钮设置日期时间轴的范围.但是,命令

f.x_range = Range1d(start=start_date, end=end_date)

不起作用.当单击按钮时,没有任何反应.无论是运行Bokeh服务器的终端窗口,还是Chrome网络浏览器的控制台输出,我都没有任何错误.

您可以在下面找到整个代码.我很感谢您的任何建议.

谢谢,

朱利安

# Import libraries
from bokeh.io import curdoc
from bokeh.models import ColumnDataSource, DatetimeTickFormatter, Select, Range1d
from bokeh.models.widgets import Button
from bokeh.layouts import layout
from bokeh.plotting import figure
from datetime import datetime, timedelta
from math import radians


# Create figure
f=figure(x_axis_type='datetime')

# Create sample datetime data
date_time = [datetime(2017,1,1) + timedelta(days=x) for x in range(0,365)]

# Create ColumnDataSource
source = ColumnDataSource(dict(datetime=date_time,parameter=range(0,365)))

# Create Line
f.line(x='datetime',y='parameter',color='olive',line_color='black',source=source)

# Update xaxis function
def update_xaxis():
    start_date = datetime(year=int(select_start_year.value), month=int(select_start_month.value), day=int(select_start_day.value))
    end_date   = datetime(year=int(select_end_year.value), month=int(select_end_month.value), day=int(select_end_day.value))    
    f.x_range = Range1d(start=start_date, end=end_date)

# Set date format for x axis
f.xaxis.formatter=DatetimeTickFormatter(formats=dict(
    seconds=["%Y-%m-%d %H:%M:%S"],
    minsec=["%Y-%m-%d %H:%M:%S"],
    minutes=["%Y-%m-%d %H:%M:%S"],
    hourmin=["%Y-%m-%d %H:%M:%S"],
    hours=["%Y-%m-%d %H:%M:%S"],
    days=["%Y-%m-%d %H:%M:%S"],
    months=["%Y-%m-%d %H:%M:%S"],
    years=["%Y-%m-%d %H:%M:%S"],
    ))
f.xaxis.major_label_orientation=radians(90)

# Create Select and Button widgets
options=[("2015","2015"),("2016","2016"),("2017","2017")]
select_start_year=Select(title="Start Year",value="2017",options=options)
options=[("01","01"),("02","02"),("03","03"),("04","04"),("05","05"),("06","06"),("07","07"),("08","08"),("09","09"),("10","10"),("11","11"),("12","12")]
select_start_month=Select(title="Start Month",value="01",options=options)
options=[("01","01"),("02","02"),("03","03"),("04","04"),("05","05"),("06","06"),("07","07"),("08","08"),("09","09"),("10","10"),("11","11"),("12","12"),("13","13"),("14","14"),("15","15"),("16","16"),("17","17"),("18","18"),("19","19"),("20","20"),("21","21"),("22","22"),("23","23"),("24","25"),("25","26"),("27","27"),("28","28"),("29","29"),("30","30"),("31","31")]
select_start_day=Select(title="Start Day",value="01",options=options)
options=[("2015","2015"),("2016","2016"),("2017","2017")]
select_end_year=Select(title="End Year",value="2017",options=options)
options=[("01","01"),("02","02"),("03","03"),("04","04"),("05","05"),("06","06"),("07","07"),("08","08"),("09","09"),("10","10"),("11","11"),("12","12")]
select_end_month=Select(title="End Month",value="06",options=options)
options=[("01","01"),("02","02"),("03","03"),("04","04"),("05","05"),("06","06"),("07","07"),("08","08"),("09","09"),("10","10"),("11","11"),("12","12"),("13","13"),("14","14"),("15","15"),("16","16"),("17","17"),("18","18"),("19","19"),("20","20"),("21","21"),("22","22"),("23","23"),("24","25"),("25","26"),("27","27"),("28","28"),("29","29"),("30","30"),("31","31")]
select_end_day=Select(title="End Day",value="01",options=options)
button = Button(label='Set Date')

# Update x axis range on click
button.on_click(update_xaxis)

# Add elements to curdoc 
lay_out=layout([[f],[select_start_year],[select_start_month],[select_start_day],[select_end_year],[select_end_month],[select_end_day],[button]])
curdoc().add_root(lay_out)

解决方法:

我想出了解决方案.首先,我使用了Datepicker小部件,它比三个Select小部件要优雅得多.然后,您必须将DateTime值从DatePicker转换为float / integer值,该值表示w.r.t所经过的秒数.一个参考日期,即1970年1月1日.Unix以秒为单位进行计算,Java Script需要以毫秒为单位的值,因此需要乘以1000.下面是代码：

# Import libraries
from bokeh.io import curdoc
from bokeh.models import ColumnDataSource, DatetimeTickFormatter, DatePicker
from bokeh.models.widgets import Button
from bokeh.layouts import layout, column, row
from bokeh.plotting import figure
from datetime import datetime, timedelta
from math import radians


# Create figure
f=figure(x_axis_type='datetime')

# Create sample datetime data
date_time = [datetime(2017,1,1) + timedelta(days=x) for x in range(0,365)]

# Create ColumnDataSource
source = ColumnDataSource(dict(datetime=date_time,parameter=range(0,365)))

# Create Line
f.line(x='datetime',y='parameter',color='olive',line_color='black',source=source)

# Update xaxis function
def update_xaxis():
    # Calculate time delta from reference time in seconds
    timestamp_start = (datetime.combine(datepicker_start.value, datetime.min.time())
                        - datetime(1970, 1, 1)) / timedelta(seconds=1)
    timestamp_end = (datetime.combine(datepicker_end.value, datetime.min.time())
                        - datetime(1970, 1, 1)) / timedelta(seconds=1)
    f.x_range.start = int(timestamp_start)*1e3  # Multiply by 1e3 as JS timestamp is in milliseconds
    f.x_range.end   = int(timestamp_end)*1e3  # Multiply by 1e3 as JS timestamp is in milliseconds

# Set date format for x axis
f.xaxis.formatter=DatetimeTickFormatter(formats=dict(
    seconds=["%Y-%m-%d %H:%M:%S"],
    minsec=["%Y-%m-%d %H:%M:%S"],
    minutes=["%Y-%m-%d %H:%M:%S"],
    hourmin=["%Y-%m-%d %H:%M:%S"],
    hours=["%Y-%m-%d %H:%M:%S"],
    days=["%Y-%m-%d %H:%M:%S"],
    months=["%Y-%m-%d %H:%M:%S"],
    years=["%Y-%m-%d %H:%M:%S"],
    ))
f.xaxis.major_label_orientation=radians(90)

# Create Datepicker and Button widgets
datepicker_start = DatePicker(title='Start Date')
datepicker_end = DatePicker(title='End Date')
button = Button(label='Set Date')

# Update x axis range on click
button.on_click(update_xaxis)

# Add elements to curdoc 
lay_out=layout([[row(f,
                     column(button,
                            row(datepicker_start,datepicker_end)))]])
curdoc().add_root(lay_out)

标签：range,axis,bokeh,datetime,python
来源： https://codeday.me/bug/20191111/2021723.html