Gradident.py

import matplotlib.pyplot as plt 
import matplotlib.animation as animation 
import numpy as np 
import math

#benis
y_data=[]
x_data=[]
fig = plt.figure('c2') 
ax = plt.axes() 
line, = ax.plot([], [], lw=4) 
def derivative(x):
    x=3+2*x+1
    return(x)
def function(x):
    x=3*x+x**2+x
    return(x)
error=5
starting_point=5
increment=.1
last=500
up_looper=starting_point*2
lw_loower=0-(starting_point*2)
range=up_looper-lw_loower
point=100
increment=range/point
plot_x=[]
plot_y=[]
x=0

while (x<point):
  x=x+1
  plot_x.append(lw_loower)
  plot_y.append(function(lw_loower))
  lw_loower=lw_loower+increment
plt.plot(plot_x,plot_y,'--')
increment=starting_point*2
y_data.append(function(starting_point))
x_data.append((starting_point))
counter=0
while(abs(error)>.05):
    if((derivative(starting_point+increment))<-1*(derivative(starting_point-increment))):
        starting_point=starting_point+increment
        error= abs(derivative(starting_point))
        last=starting_point
    
    else:
        starting_point=starting_point-increment
        error= last-starting_point
        last=starting_point
    y_data.append(function(starting_point))
    x_data.append((starting_point))
    if starting_point==0:
      break
    counter=counter+1
    increment=increment*(.75)
print(starting_point)
print(len(x_data))
# initialization function 
def init(): 
    # creating an empty plot/frame 
    line.set_data([], []) 
    return line, 
  
# lists to store x and y axis points 
xdata, ydata = [], [] 
  
# animation function 
def animate(i): 
      
    # x, y values to be plotted 
    x = x_data[i]
    y = y_data[i]
      
    # appending new points to x, y axes points list 
    xdata.append(x) 
    ydata.append(y) 
      
    # set/update the x and y axes data 
    line.set_data(xdata, ydata) 
      
    # return line object 
    return line, 
      
# setting a title for the plot 
plt.title('Gradient Descent!') 
  
# call the animator     
anim = animation.FuncAnimation(fig, animate, init_func=init, frames=int(len(y_data)), interval=1, blit=True) 
  
# save the animation as mp4 video file 
writergif=animation.PillowWriter(fps=30)
anim.save('Visual.gif', writer =animation.PillowWriter(fps=10) ) 

#plt.plot(t**3) 
plt.show()