Online Bokeh App Compiler

How to use the Bokeh library to create a simple app with sliders and a plot

Python
import numpy as np

from bokeh.io import curdoc
from bokeh.layouts import column, row
from bokeh.models import ColumnDataSource, Slider, TextInput
from bokeh.plotting import figure

# Set up data
N = 200
x = np.linspace(0, 4*np.pi, N)
y = np.sin(x)
source = ColumnDataSource(data=dict(x=x, y=y))


# Set up plot
plot = figure(height=400, width=400, title="my sine wave",
            tools="crosshair,pan,reset,save,wheel_zoom",
            x_range=[0, 4*np.pi], y_range=[-2.5, 2.5])

plot.line('x', 'y', source=source, line_width=3, line_alpha=0.6)


# Set up widgets
amplitude = Slider(title="amplitude", value=1.0, start=-5.0, end=5.0, step=0.1)
phase = Slider(title="phase", value=0.0, start=0.0, end=2*np.pi)
freq = Slider(title="frequency", value=1.0, start=0.1, end=5.1, step=0.1)


def update_data(attrname, old, new):
    # Get the current slider values
    a = amplitude.value
    w = phase.value
    k = freq.value

    # Generate the new curve
    x = np.linspace(0, 4*np.pi, N)
    y = a*np.sin(k*x + w)

    source.data = dict(x=x, y=y)

for w in [amplitude, phase, freq]:
    w.on_change('value', update_data)


# Set up layouts and add to document
inputs = column(amplitude, phase, freq)

curdoc().add_root(row(inputs, plot, width=800))
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