Did you read the documentation before you read the code?
‘%%’ and ‘x %/% y’ can be used for non-integer ‘y’, e.g. ‘1 %/%
0.2’, but the results are subject to rounding error and so may be
platform-dependent. Because the IEC 60059 representation of ‘0.2’
is a binary fraction slightly larger than ‘0.2’, the answer to ‘1
%/% 0.2’ should be ‘4’ but most platforms give ‘5’.
I suspect that is relevant to your interests....
Yes. I think José is assuming that 25 %/% 0.2 and floor(25/0.2) are
equal, but they are not, because rounding affects them differently.
(The first is a single operation with no rounding except in the
representation of 0.2; the second is two operations and is subject to
another set of rounding.)
Duncan Murdoch
Thank you (both) very much for the info. Indeed I wasn't aware of that
piece of documentation and of the implications of rounding. Excuse me
for my hasty question when facing this behaviour.
--
---------------------------------------
José M. Blanco-Moreno
Dept. de Biologia Vegetal (Botànica)
Facultat de Biologia
Universitat de Barcelona
Av. Diagonal 645
08028 Barcelona
SPAIN
---------------------------------------
phone: (+34) 934 039 863
fax: (+34) 934 112 842
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