How to use format as an alternative to `round` to convert a small number to zero?

Asked Jun 14 '22 at 13:00

Active Jun 23 '22 at 16:03

Viewed 51 times

There is a point in my program where I compare a number with zero and if it is zero I execute a series of commands. The number calculated should be zero for some conditions but it just comes out to be a really small number (**(-17)) instead of exactly zero. So, I am planning to use format to rectify that by making very small numbers zero. I test ran this below and this simple code did not work.

I avoided using round because that might hinder the precision I want in my my code.

Is there a way implement format so that it works how I want it to?

Here:

a='{:.5f}'.format(0.00000056)
print(a)
if a==0.:
  print('success')

output:

0.00000

edited Jun 23 '22 at 16:03

asked Jun 14 '22 at 13:00

Lost

2

`a` contains a string; you are comparing it to a number. – Scott Hunter Jun 14 '22 at 13:02
1

`if your_number < 0.00001: print('success')` ?? – 001 Jun 14 '22 at 13:04
maybe you want this instead of doing it via string formatting https://docs.python.org/3/library/functions.html#round – Anentropic Jun 14 '22 at 13:19
@Anentropic rounding off may increase error but I'll check how much does the answer deviate with this. Thanks – Lost Jun 14 '22 at 13:42
@Johny Mopp ya that seems like what I want to do but I do not understand why `0.1-0.1` is not simply zero in python. – Lost Jun 14 '22 at 13:44
it is `In [4]: 0.1 - 0.1 == 0` `Out[4]: True` – Anentropic Jun 14 '22 at 13:45
this may also be useful https://docs.python.org/3/library/math.html#math.isclose – Anentropic Jun 14 '22 at 13:48
1

[Is floating point math broken?](https://stackoverflow.com/q/588004) – 001 Jun 14 '22 at 14:15

How to use format as an alternative to `round` to convert a small number to zero?

0 Answers0