使用 jupyter 笔记本中的散景小部件更新散景图

Question

我想使用 jupyter 笔记本中的散景小部件来更新散景图。我的（有点hacky）代码如下所示：

from bokeh.plotting import figure
from bokeh.io import output_notebook, push_notebook, show
from bokeh.models import CustomJS, Slider

output_notebook()

power = 0.5
x = [1,2,3]
y = [i**power for i in x]

fig = figure()
plt = fig.circle(x, y)

def update_plot(power):
    x = plt.data_source.data['x']
    plt.data_source.data['y'] = [i**power for i in x]
    push_notebook(handle=bokeh_handle)  


bokeh_handle = show(fig, notebook_handle=True)

##### new notebook cell #####

callback = CustomJS(code="""
if (IPython.notebook.kernel !== undefined) {
    var kernel = IPython.notebook.kernel;
    cmd = "update_plot(" + cb_obj.value + ")";
    kernel.execute(cmd, {}, {});
}
""")

slider = Slider(start=0.1, 
                end=1,
                value=1,
                step=.05,
                title="power",
                callback=callback)
show(slider)

这个想法是滑块的 JS 回调调用 python 函数update_plot()，该函数更改散景图的数据，然后触发push_notebook().

但是，当我移动滑块时，绘图没有更新，但左上角出现一些奇怪的字形（参见红色箭头）。

执行print(plt.data_source.data['y'])告诉我，回调update_plot()实际上是在滑块移动时调用的。为什么剧情没有正确更新？或者我在这里遗漏了什么？

（我知道我可以使用 做同样的事情ipywidgets.interact，但我想坚持使用散景小部件。）

Answer 1

我通过在布局中显示图形和滑块小部件来按预期更新绘图bokeh.layouts.row：

from bokeh.plotting import figure
from bokeh.io import output_notebook, push_notebook, show
from bokeh.models import CustomJS, Slider
from bokeh.layouts import row

output_notebook()

power = 0.5
x = [1,2,3]
y = [i**power for i in x]

fig = figure()
plt = fig.circle(x, y)

def update_plot(power):
    x = plt.data_source.data['x']
    plt.data_source.data['y'] = [i**power for i in x]
    push_notebook(handle=bokeh_handle)  


##### new notebook cell #####

callback = CustomJS(code="""
if (IPython.notebook.kernel !== undefined) {
    var kernel = IPython.notebook.kernel;
    cmd = "update_plot(" + cb_obj.value + ")";
    kernel.execute(cmd, {}, {});
}
""")

slider = Slider(start=0.1, 
                end=1,
                value=1,
                step=.05,
                title="power",
                callback=callback)
bokeh_handle = show(row(fig, slider), notebook_handle=True)