Re: sub as mathematical function

Assuming $v is in [0..1)

sub quant {
   my $v = shift;
   return int($v*9);
}
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Re^2: sub as mathematical function by vr (Curate) on Sep 04, 2019 at 21:04 UTC
Measure (and cost) of returning "exactly the same" result unspecified, a pedant would note it's pure luck and coincidence that for 9 intervals these functions indeed seem to always return the same. For a simple case of 6 intervals: `~$ perl -E 'say 4 if 0.8333333333333333 < 5/6' 4 ~$ perl -E 'say int 6 * 0.8333333333333333' 5` [download] For maybe general case of 100 intervals, playing with Data::Float (and from similar experiment literal number above came from): `~$ perl -MData::Float=nextdown -E '$n=100; for(1..$n){say if $_-1 != i +nt $n*nextdown $_/$n}' 5 10 17 20 23 34 40 46 67 68 80 81 92 93` [download]	[reply] [d/l] [select]

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Re^2: sub as mathematical function
by vr (Curate) on Sep 04, 2019 at 21:04 UTC

Measure (and cost) of returning "exactly the same" result unspecified, a pedant would note it's pure luck and coincidence that for 9 intervals these functions indeed seem to always return the same. For a simple case of 6 intervals:

~$ perl -E 'say 4 if    0.8333333333333333 < 5/6'
4
~$ perl -E 'say int 6 * 0.8333333333333333'
5
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For maybe general case of 100 intervals, playing with Data::Float (and from similar experiment literal number above came from):

~$ perl -MData::Float=nextdown -E '$n=100; for(1..$n){say if $_-1 != i
+nt $n*nextdown $_/$n}'
5
10
17
20
23
34
40
46
67
68
80
81
92
93
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