Re: To get the accurate value of 1 - 0.999999999999999 ,how to implement the python algorithm ?

Ulrich Eckhardt ulrich.eckhardt at dominolaser.com
Mon Oct 8 10:44:01 EDT 2012


Am 08.10.2012 16:07, schrieb iMath:
> To get the accurate value of 1 - 0.999999999999999 ,how to implement the python algorithm ?

Algorithms are generally language-agnostic, so what is your question

> BTW ,Windows’s calculator get the accurate value ,anyone who knows how to implement it ?

You should use a library that handles arbitrary-precision floating point 
numbers, Python's built-in floating point type corresponds to C's double 
type and that is typically a IEEE float, which means a limited 
precision. Just search the web for one. If you really want to do it 
yourself, you could leverage the fact that Python's integral type has a 
dynamic size, so that it can represent numbers with more than the 
typical 32 or 64 bits width.

BTW: If this is not a homework question, you should ask much more 
specifically. My anwers are intentionally vague in order to not spoil 
you the learning effect.

Cheers!

Uli





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