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python - 滑块值未更新 Bokeh Python

问题描述

我在 Jupyter Notebook 中使用 Bokeh 制作交互式情节时遇到了困难。我想绘制一张世界地图并显示一些数据随时间的发展。我成功地制作了一个绘图并有一个滑块来调整年份，但是当我更改滑块时，滑块值不会更新。滑块的代码如下：

#creating the data source as a dict
source = ColumnDataSource({
    'x': p_df['x'], 
    'y': p_df['y'], 
    'Country': p_df['Country'], 
    'nkill': p_df['nkill']
})

#making a slider and assign the update_plot function to changes
slider = Slider(start=start_yr, end=end_yr, step=1, value=start_yr, title='Year')
slider.on_change('value',update_plot)

#the update_plot function which needs to run based on the new slider.value
def update_plot(attr, old, new):
    #Update glyph locations
    yr = slider.value
    Amountkills_dt_year = p_df[p_df['Year'] ==yr]
    new_data = {
        'x': Amountkills_dt_year['x'], 
        'y': Amountkills_dt_year['y'], 
        'Country': Amountkills_dt_year['Country'], 
        'nkill': Amountkills_dt_year['nkill']
    }
    source.data = new_data
    #Update colors
    color_mapper = LinearColorMapper(palette='Viridis256',
                                 low = min(Amount_of_Terrorist_Attacks['nkill']),
                                 high = max(Amount_of_Terrorist_Attacks['nkill']))

我想用 update_plot() 函数更新绘图的地方。我尝试了Python bokeh slider not refresh plot中的解决方案，但我仍然遇到了同样的错误。

标签： pythonpython-3.xsliderbokehinteractive

解决方案

像滑块这样的散景小部件在 jupyter 笔记本中不起作用（至少，在不使用一些 JavaScript 的情况下是这样）。正如文档所说：

To use widgets, you must add them to your document and define their functionality. Widgets can be added directly to the document root or nested inside a layout. There are two ways to program a widget’s functionality:

        Use the CustomJS callback (see JavaScript Callbacks). This will work in standalone HTML documents.

        Use bokeh serve to start the Bokeh server and set up event handlers with .on_change (or for some widgets, .on_click).

正如@bigreddot 所暗示的那样，您将需要使用散景服务器，或者可能需要使用此处讨论的 jupyter 交互器讨论中的一些功能。

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