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Postings from October 2003
In message <200310072341.47898@bloodgate.com> (on 7 October 2003 23:41:46
+0200), perl_dummy@bloodgate.com (Tels) wrote:
>But why does
>
> perl -le "print +(81**3)**(1/3)"
>
>print 81 and not 80.99999999999999? perldoc print only says that it will
>print "a string or list of strings" but doesn't mention how print creates
>the strings. I guess it uses sprintf ("%.0f") or something internally when
>it sees a scalar containing a float, but I couldn't find the place where is
>documented how print converts floats to a string. (I am not saying that it
>isn't in the doc - I just don't know where to look for it. Where is
>perlgoogle when you need it...)
Quite. It's buried in one of the deprecated variables in perlvar:
$# The output format for printed numbers. This variable is a
half-hearted attempt to emulate awk's OFMT variable. There are
times, however, when awk and Perl have differing notions of
what is in fact numeric. The initial value is %.ng, where n is
the value of the macro DBL_DIG from your system's float.h.
This is different from awk's default OFMT setting of %.6g, so
you need to set "$#" explicitly to get awk's value. (Mnemonic:
# is the number sign.)
-Allen
--
Allen Smith http://cesario.rutgers.edu/easmith/
February 1, 2003 Space Shuttle Columbia
Ad Astra Per Aspera To The Stars Through Asperity