To plot rays on a graph using Bokeh in Python, you can follow these steps:

- Import the necessary libraries:

import numpy as np from bokeh.io import output_notebook, show from bokeh.plotting import figure

- Define the starting and ending points of the rays:

x_start = [0, 1, 2, 3, 4] y_start = [0, 0, 0, 0, 0] x_end = [2, 3, 4, 5, 6] y_end = [1, 2, 3, 4, 5]

- Create a Bokeh figure:

p = figure(plot_width=400, plot_height=400)

- Plot the rays using the
`ray`

function:

for i in range(len(x_start)): p.ray(x=x_start[i], y=y_start[i], angle=np.arctan2(y_end[i]-y_start[i], x_end[i]-x_start[i]), length=0, line_width=2)

- Show the plot:

show(p)

This will create a plot with rays starting at the coordinates `(x_start[i], y_start[i])`

and ending at the coordinates `(x_end[i], y_end[i])`

. The `angle`

parameter is calculated using `np.arctan2()`

to find the angle between the starting and ending points, and the `length`

parameter is set to `0`

to draw the rays infinitely long. The `line_width`

parameter controls the thickness of the rays.

### plotting.figure.ray()

`plotting.figure.ray()`

is a function in Bokeh, which is used to plot a ray on a figure. A ray is a line segment that extends infinitely in one direction from a given starting point.

The `plotting.figure.ray()`

function takes several arguments:

`x`

: the x-coordinate of the starting point of the ray`y`

: the y-coordinate of the starting point of the ray`length`

: the length of the ray (can be set to`0`

to draw a ray that extends infinitely)`angle`

: the angle (in radians) of the direction in which the ray extends`color`

: the color of the ray`line_width`

: the width of the line used to draw the ray`line_dash`

: the dash pattern of the line used to draw the ray

Here’s an example of how to use `plotting.figure.ray()`

to plot a ray on a Bokeh figure:

from bokeh.plotting import figure, show # Create a Bokeh figure p = figure(plot_width=400, plot_height=400) # Plot a ray from (0,0) to (1,1) p.ray(x=0, y=0, angle=45, length=0, line_width=2) # Show the plot show(p)

This will plot a ray starting at the point `(0,0)`

and extending in the direction of 45 degrees (i.e., northeast) indefinitely.

### Conclusion:

In this conversation, we discussed how to plot rays on a graph using Bokeh in Python. We outlined the steps involved, including importing the necessary libraries, defining the starting and ending points of the rays, creating a Bokeh figure, and using the `ray()`

function to plot the rays on the figure. We also provided an example of how to use the `ray()`

function to plot a ray on a Bokeh figure. Overall, Bokeh is a powerful Python library that allows for the creation of interactive visualizations and can be used to create a wide range of plots, including rays, lines, scatter plots, and more.