Difffration grating code

import numpy as np
import matplotlib.pyplot as plt
n=45 # Value of the refractive index
d=0.02  #Slit separation value
L=500e-6  #The Wavelength value
theta_i=np.linspace(0,100,10)*np.pi/180 # the incident angle
print(theta_i) #printing theta_i values
theta_n=np.arcsin(n*L/d-np.sin(theta_i)) # the diffraction angle
s=theta_n*180/np.pi # diffraction angle is converted to degrees
plt.xlim(10,90)   #setting the x axis limits (scale)
plt.ylim(0,80)   #setting the y axis limits (scale)
plt.plot(theta_i*180/np.pi,s)  # x axis is converted to degrees then plotting x and y axis
plt.xlabel("theta_i")  #x axis labeling
plt.ylabel("theta_n")  #y axis labeling
plt.title("Diffraction angle as a function of incident angle") #Title labeling
plt.show() #this command was written to show the graph