mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 05:21:09 +00:00
beafe3656f
* Change some Image File names & re-code the psnr algorithm (conserving both methods). Also Added new example. * Selected psnr method and reformat some code from arithmetic_analysis
34 lines
964 B
Python
34 lines
964 B
Python
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) / 2
|
|
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) / 2
|
|
return mid
|
|
|
|
|
|
def f(x):
|
|
return math.pow(x, 3) - 2*x - 5
|
|
|
|
if __name__ == "__main__":
|
|
print(bisection(f, 1, 1000))
|