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Perl: the Markov chain saw

Re: Perl returns NaN after addition

by syphilis (Chancellor)
on Oct 17, 2013 at 01:35 UTC ( #1058577=note: print w/replies, xml ) Need Help??

in reply to Perl returns NaN after addition

Could it be that it's too large for perl? or it could be a non-numeric variable in the data file, so how would I test for that?

You can get a result of "NaN" by doing addition *only* if one (or more) of the values being summed is a NaN.
I would therefore check the terms being added to see if any of them match the regex /^nan/i .


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Re^2: Perl returns NaN after addition
by tinita (Parson) on Oct 17, 2013 at 01:42 UTC
    or, if the OP happens to use Math::BigFloat:
    $ perl -MMath::BigFloat -wE 'say Math::BigFloat->new(5) + "foo"' NaN
      or, if the OP happens to use Math::BigFloat

      It's interesting that Math::BigFloat decides it has to numify a non-numeric string to NaN ... when everything else numifies such a string to zero.

      Actually, I'm tempted to s/interesting/stupid/, but maybe there's a precedent somewhere that gives some credence to the Math::BigFloat behaviour.


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