Re: significant digits in computations

Never underestimate the power of CPAN:

  Math::SigFigs - do math with correct handling of significant figures

  In many scientific applications, it is often useful to be
  able to format numbers with a given number of significant
  figures, or to do math in such a way as to maintain the
  correct number of significant figures.  The rules for
  significant figures are too complicated to be handled
  solely using the sprintf function (unless you happen to be
  Randal Schwartz :-).

Comment on Re: significant digits in computations

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Re^2: significant digits in computations by hepcat72 (Sexton) on Mar 04, 2014 at 16:33 UTC
I just rolled my own significant digits subroutines and felt like I should look it up to see what other people have done before I start incorporating it in any apps I roll out - in case anyone handled it better. I took a look at Math::SigFigs, and I'm not sure I agree with the way some of the numbers are handled. First, I've never seen a number with a trailing decimal point to suggest that any trailing zeroes to the left of it are significant. Without that decimal point, the module assumes that all trailing zeros in whole numbers are not significant, but while I understand the intent here, I'd be wary of the output. 0 is a digit just like any other and does not necessarily convey significance when the number ends with some number of zeros. You could have any number of trailing zeros and any fraction of them could be significant. Also, the module does not handle exponents. I wrote my code to extract the number from the left of the exponent and make a recursive call with it, tacking the exponent back on when it comes back. This module just returns undef. That said, this module appears written more efficiently than my attempt - just be aware of the caveats.	[reply]
RE: Re: significant digits in computations by lhoward (Vicar) on Jun 12, 2000 at 23:17 UTC
This is just what I was talking about in my earlier post. I only wish it had a better (object oriented) interface that could be used transparently in arithmetic. Doing a complicated formula using Math::SigFigs seems like a lot of trouble.	[reply]