How do I round up a number to the next integer with a high precision?
Input: var1 = (8193/4096) # var1 = 2.00024414063
Output: 3 # As an integer
>>> var1 = 8193/4096
>>> import math
>>> math.ceil(var1)
2.0
>>> math.ceil(8193/4096)
2.0
>>> import numpy
>>> numpy.ceil(8193/4096)
How can I elegantly do this operation?
In Python 2, this:
>>> var1 = 8193/4096
doesn't do what you think it does. In Python 2, dividing two integers always returns an integer (truncated) as the result.
>>> 8193/4096
2
...and then calling math.ceil() on 2 returns 2.
Convert one or both of your values to a floating point value and it will do what you like:
>>> v = 8193/4096.0
>>> v
2.000244140625
>>> math.ceil(v)
3.0
Alternatives:
a) switch to Python 3, where division does behave like you want it to:
bgporter@zappa:~$ python3
Python 3.4.0 (default, Apr 11 2014, 13:05:18)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 8193/4096
2.000244140625
>>>
b) enable Python 3's division on Python 2 like this:
bgporter@varese ~:python
Python 2.7.5 (default, Mar 9 2014, 22:15:05)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from __future__ import division
>>> 8193/4096
2.000244140625