Python Data Visualization Cookbook (Second Edition)

Plotting a 3D trefoil knot

In this recipe, we will see how to plot a 3D trefoil knot. A trefoil knot is a closed curve with three crossings. In this recipe, we will draw not just a curve, but a solid 3D curve. This is beyond the plotly capabilities, and we will implement this functionality using a trick.

How to do it...

In this recipe, we will:

1. Generate all the points of the knot using parametric equations.
2. Organize the data as required by plotly.
3. Define a clean layout.
4. Invoke plotly to draw the chart:

   import numpy as np import plotly.plotly as py from plotly.graph_objs import Scatter3d, Data, Layout from plotly.graph_objs import Figure, Line, Margin, Marker from numpy import linspace,pi,cos,sin phi = linspace(0,2*pi,250) x = sin(phi)+2*sin(2*phi) y ...