Have you seen the update in my reply?

Floats are automatically adjusted to avoid leading zeros in the mantissa.


Think float, this

x1 = 256080 x2 = 258160 diff = 2080.00000000003

really just means (in slightly inaccurate decimal interpretation)

x1 = 2.56080 e5 x2 = 2.5816000000000003 e5 (error ignored when printed) diff = 2.08000000000003 e3 (error visible when printed)

As you can see the error (here decimal 3) is shifted to the left and out of error margin into printed "visibility".


after firing up my laptop, here a proof of concept

DB<115> $x1 = 2.56080e5 => 256080 DB<116> $x2 = 2.5816000000000003e5 => 258160 # within error margin, ignored in normal di +splay DB<117> printf '%.11f', $x2 258160.00000000003 # forced into visibility, hence $x2 NOT an +integer DB<118> $x2-$x1 => 2080.00000000003 # error can't be ignored any more

Cheers Rolf
(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!

In reply to Re^3: Integers sometimes turn into Reals after substraction (printed accuracy and float subtraction) by LanX
in thread Integers sometimes turn into Reals after substraction by rduke15

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