This question already has answers here:
How can I use "e" (Euler's number) and power operation?
(7 answers)
Closed 3 months ago.
What is the easiest/most optimal way of finding the exponential of a number, say x, in Python? i.e. how can I implement e^x?
The easiest and most optimal way to do e^x in Python is:
from math import exp
print(exp(4))
Output
>>> 54.598150033144236
You can use the math.exp() function from the math module (read the docs).
>>> import math
>>> x = 4
>>> print(math.exp(x))
54.598150033144236
Related
This question already has answers here:
Limiting floats to two decimal points
(35 answers)
how to format float number in python? [duplicate]
(3 answers)
variable number of digit in format string
(3 answers)
Closed 1 year ago.
I'm reading this textbook called "Practical Statistics for Data Scientists" and this :.3f keeps getting used in almost every f-string. What does :.3f mean? My guess is it has something to do with floating point numbers.
Example:
{house_lm_factor.intercept_:.3f}
This is show you how many number are printing:
>>> import math
>>> flt = math.pi
>>> f'{flt:.3f}'
'3.142'
>>> f'{flt:.5f}'
'3.14159'
>>> f'{flt:.10f}'
'3.1415926536'
This question already has answers here:
Round to 5 (or other number) in Python
(21 answers)
How do I round to the nearest 0.5?
(10 answers)
Closed 2 years ago.
I got this number 1.12412 and I want to round it to 1.12415 or 1.12410 (muliple of 5 in last decimal)
If using the Round(X,4) function I get 1.1241 (4 decimals).
Is there a function that can make that happen?
Thanks!
There is an answer in stack but using c# not python
My way to do that is to specify rounding unit first and then simple trick as below:
import numpy as np
rounding_unit = 0.00005
np.round(1.12412/rounding_unit) * rounding_unit
You may:
Multiply your number by 2
Use Round(X,4)
Divide the result by 2
profit!!!
This question already has answers here:
What is the best way to compare floats for almost-equality in Python?
(18 answers)
Closed 3 years ago.
I have two numbers, one I get by calculating it and the other one I bring it from the database.
calculated = 2.183333333333333
database = 2.18333333333333
But when I compare them to know if they are the same, I return False when it should be True.
There is some way to limit the number of periodic numbers, but not to affect decimals that are not periodic, for example:
2.1748888888888 -> 2.1748
1.23333333 -> 1.23
You could use the math.isclose method:
>>> from math import isclose
>>> calculated = 2.183333333333333
>>> database = 2.18333333333333
>>> isclose(calculated, database)
True
This allows for setting the relative tolerance and minimum absolute tolerance as well refer to the docs for more explanation.
This question already has answers here:
Math operations from string [duplicate]
(8 answers)
Evaluating a mathematical expression in a string
(14 answers)
Closed 3 years ago.
I am fairly new to python/ programming in general and i am trying to write a function that will convert an equation passed in as a string to its numeric representation and do some basic calculations. I am having some trouble with the parenthesis as i am not sure how to represent them for order of operations.
Any help of tips would be greatly appreciated. Thank you!
EquationAsString ="( 2 + 3 ) * 5"
def toEquation(EquationAsString):
Equation = EquationAsString.split(' ')
#store info in list and use it like a stack, check the type etc.
answer = 25
return answer
You can use the eval method to do such a thing.
Example:
print(eval('(2+3)*5'))
Output:
25
And if you really wanted to put it in a function:
def evaluation_string(input):
print(eval(input))
Example
def evaluation_string(input):
print(eval(input))
string_equation = '(2+3)*5'
evaluation_string(string_equation)
Output:
25
This question already has answers here:
Evaluate math equations from unsafe user input in Python
(2 answers)
Closed 4 years ago.
How do you turn a string gathered from input into an actual function? For example,
>>>function = input("Enter a function: ")
>>>Enter a function: "sin(t)"
And then I'd be able to use the entered function. Is there a library to parse through the string and return a math function like so?
You can use exec
>>> import math
>>> t=45
>>> exec('s=math.sin(t)')
>>> s
0.8509035245341184
>>>
Or if you just want the function
>>> exec('f=math.sin')
>>>
>>> f(45)
0.8509035245341184
>>>