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Python Graphs and Charts

Posted by Pattarakorn Tussanapirom
Pattarakorn Tussanapirom
2,467 Points

Graph not show

I have followed steps given in the video but graph is still not show up. My output is <function __main__.update (f, w=1, A=1, phi=0)>

2 Answers

Megan Amendola
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STAFF
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Megan Amendola
Treehouse Teacher
Megan Amendola
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Megan Amendola
Treehouse Teacher

Hi! Did you enable JavaScript to run in your notebook? Kenneth shows how to do this in the video starting at about 1:38. The code to run in your terminal is in the teacher's notes.

Jessica Dobson
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Jessica Dobson
Data Analysis Techdegree Graduate 33,377 Points
Jessica Dobson
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Jessica Dobson
Data Analysis Techdegree Graduate 33,377 Points

I have the same output as above, but running the code in the teacher's notes doesn't work because I'm in Jupyter 7 and it just keeps saying nbextenstion not found.

Sharina Jones
Sharina Jones
6,700 Points
Sharina Jones
Sharina Jones
6,700 Points

Installing Visualization Libraries

You can install the necessary packages using either pip or conda:

Using pip (inside or outside a notebook):

!pip install numpy bokeh panel

Or using conda:

conda install numpy bokeh -c conda-forge
conda install panel -c pyviz

Once installed, restart your Jupyter kernel to ensure the libraries are available.

Enabling Panel in JupyterLab

Panel works out of the box in JupyterLab version 3 and later (including version 4.3.4). You do not need to enable extensions manually. Just make sure you initialize it in your notebook with:

import panel as pn
pn.extension()

Creating an Interactive Plot with Panel and Bokeh

Paste the following code into a new notebook cell to create an interactive wave plot:

import numpy as np
import panel as pn
from bokeh.plotting import figure
from bokeh.io import output_notebook

pn.extension()
output_notebook()

# Create initial data
x = np.linspace(0, 2 * np.pi, 2000)
y = np.sin(x)

# Set up the plot
p = figure(title='Interactive Wave Plot', height=300, width=600, y_range=(-5, 5))
r = p.line(x, y, color='navy', line_width=3)

# Define the update function
def update(f="sin", w=1, A=1, phi=0):
    func = {"sin": np.sin, "cos": np.cos, "tan": np.tan}[f]
    r.data_source.data['y'] = A * func(w * x + phi)

# Create widgets
f_widget = pn.widgets.Select(name='Function', options=["sin", "cos", "tan"], value="sin")
w_widget = pn.widgets.IntSlider(name='Frequency (w)', start=0, end=100, value=1)
A_widget = pn.widgets.IntSlider(name='Amplitude (A)', start=1, end=5, value=1)
phi_widget = pn.widgets.FloatSlider(name='Phase (phi)', start=0, end=20, step=0.1, value=0)

# Bind widgets to function
pn.bind(update, f=f_widget, w=w_widget, A=A_widget, phi=phi_widget)

# Layout and display
layout = pn.Row(pn.Column(f_widget, w_widget, A_widget, phi_widget), p)
layout

This layout uses Panel to create a live-updating graph of sine, cosine, and tangent waves. You can control the frequency, amplitude, and phase using sliders, and switch wave types using a dropdown menu.