%matplotlib inline #省去plt.show() %config Completer.use_jedi=False #jupyter 补全代码太慢解决办法
import numpy as np from IPython import display from d2l import torch as d2l1.导数
f ′ ( x ) = lim h → 0 f ( x + h ) − f ( x ) h f^{'}(x) = lim_{h to 0}frac{f(x+h)-f(x)}{h} f′(x)=limh→0hf(x+h)−f(x)
def f(x):
return 3*x**2-4*x
def numerical_lim(f,x,h):
return (f(x+h)-f(x))/h
h=0.1
for i in range(5):
print(f'h={h:.5f},numerical limit = {numerical_lim(f,1,h):.5f}')
h *= 0.1
h=0.10000,numerical limit = 2.30000 h=0.01000,numerical limit = 2.03000 h=0.00100,numerical limit = 2.00300 h=0.00010,numerical limit = 2.00030 h=0.00001,numerical limit = 2.00003
