How matplotlib automatically set x-axis and y-axis limits for bar graph ?

[ift38375]

Hi,

I am confused in math/logic behind automatically by-default setting of x-axis and y-axis limits in bar graph ? Here i am sharing some examples

1.

import matplotlib.pyplot as plt
x = [1,2,3,4,5]
y = [1000, 1002, 1001, 1003, 1005]
plt.bar(x,y) 
plt.show()

In this bar graph, X axis limits are 0,1,2,3,4,5 and Y axis limits are 0,200,400,600,800,1000. How is happened??

2.

import matplotlib.pyplot as plt
x=[20,30,90,70, 50, 60, 80, 70]
y=[3,2,5,10, 3, 9, 7, 6]
plt.bar(x,y)
plt.show()

In this bar graph, X axis limits are 0,20,30,40,50,60,70,80,90 and Y axis limits are 0,2,4,6,8,10. How is happened??