Bokeh

Question

请问如何使用用户 Select 小部件更新滑块的最小值和最大值 index_min 和 index_max？例如，选择U1时，滑块的最小值和最大值应为2586和2836。

import pandas as pd
from bokeh.layouts import column, layout
from bokeh.models import ColumnDataSource, Select, Slider
from bokeh.io import curdoc
from bokeh.plotting import figure

df = pd.DataFrame({'Time': [2586, 2836, 2986, 3269, 3702],
                   'X': [120, 210, 80, 98, 40],
                   'Y': [230, 40, 33, 122, 10],
                   'User': ['u1', 'u1', 'u2', 'u2', 'u2'],
                   'img': ['tree1.png', 'tree2.jpg', 'tree3.jpg', 'tree4.jpg','tree5.jpg']})

source = ColumnDataSource(data=dict(time=[], x=[], y=[], user=[], img=[]))

options = sorted(set(df['User']))
user_options = ['Please select ...'] + options
users = Select(title="User:", value=user_options[0], options=user_options)

index_min = df['Time'].min()
index_max = df['Time'].max()
index = Slider(start=index_min, end=index_max, value=index_max , step=1, title="Time Index")

def select_user():
    user_val = users.value
    selected = df[(df.Time <= index.value)]
    if (user_val != ""):
        selected = selected[selected.User.str.contains(user_val)==True]
    return selected

def update():
    dfnew = select_user()
    source.data = dict(time=dfnew['Time'], x=dfnew['X'], y=dfnew['Y'], user=dfnew['User'], img=dfnew['img'])


controls = [users, index]
for control in controls:
    control.on_change('value', lambda attr, old, new: update())


p = figure(plot_width = 600, plot_height = 600)
p.circle(x="x", y="y", source=source, legend='user')


update() # initial load of the data

l = layout(column(users, index, p))

curdoc().add_root(l)

Answer 1

这是我的做法。

import pandas as pd

from bokeh.io import curdoc
from bokeh.layouts import column
from bokeh.models import ColumnDataSource, Select, Slider

df = pd.DataFrame({'Time': [2586, 2836, 2986, 3269, 3702, 1, 2],
                   'X': [120, 210, 80, 98, 40, 0, 1],
                   'Y': [230, 40, 33, 122, 10, 1, 2],
                   'User': ['u1', 'u1', 'u2', 'u2', 'u2', 'u3', 'u4'],
                   'img': ['tree1.png', 'tree2.jpg', 'tree3.jpg', 'tree4.jpg', 'tree5.jpg', 'x', 'x']})

source = ColumnDataSource(data=dict(time=[], x=[], y=[], user=[], img=[]))

user_options = [('', 'Please select ...')] + [(o, o) for o in sorted(set(df['User']))]
users = Select(title="User:", value=user_options[0][0], options=user_options)

index = Slider(start=0, end=1, value=0, step=1, title="Time Index")


def filter_by_user(user):
    if user:
        return df[df['User'] == user]
    return df


def on_user_change(attr, old, new):
    selected = filter_by_user(new)
    start = selected['Time'].min()
    end = selected['Time'].max()
    index.update(start=start,
                 end=end + 1 if start == end else end,
                 value=start,
                 disabled=start == end)


users.on_change('value', on_user_change)


def on_index_change(attr, old, new):
    selected = filter_by_user(users.value)
    dfnew = selected[selected['Time'] <= new]
    # Note: if you rename your df columns to all lower-case, then you can just use `ColumnDataSource.from_df()`.
    source.data = dict(time=dfnew['Time'], x=dfnew['X'], y=dfnew['Y'], user=dfnew['User'], img=dfnew['img'])


index.on_change('value', on_index_change)

# Just to populate the initial data.
on_user_change(None, None, '')

curdoc().add_root(column(users, index))

Bokeh - 如何使用 Select 小部件更新滑块的最小值、最大值？

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