FilesExpand file tree

 all-permutations

/

bisection.py

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

33 lines (27 loc) · 984 Bytes

 all-permutations

/

bisection.py

Top

File metadata and controls

• Code
• Blame

33 lines (27 loc) · 984 Bytes

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

import math

def bisection(function, a, b): # finds where the function becomes 0 in [a,b] using bolzano

start = a

end = b

if function(a) == 0: # one of the a or b is a root for the function

return a

elif function(b) == 0:

return b

elif function(a) * function(b) > 0: # if none of these are root and they are both positive or negative,

# then his algorithm can't find the root

print("couldn't find root in [a,b]")

return

else:

mid = start + (end - start) / 2.0

while abs(start - mid) > 10**-7: # until we achieve precise equals to 10^-7

if function(mid) == 0:

return mid

elif function(mid) * function(start) < 0:

end = mid

else:

start = mid

mid = start + (end - start) / 2.0

return mid

def f(x):

return math.pow(x, 3) - 2*x - 5

if __name__ == "__main__":

print(bisection(f, 1, 1000))