Re: Re: Help with decimals

Your plucking the digits off one end, sticking on the dot, and sticking them back on sounds like something a regex should do!

$number .= '0'  while length($number) < $places;
  # add trailing zeros if needed
$number =~ /(.{$places})/\.$1/;
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Or a substr

# add trailing zeros, as above.
substr ($number, -$places, 0, '.');
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Re: Re: Re: Help with decimals by rchiav (Deacon) on Jul 31, 2001 at 01:45 UTC
Acutally a regex isn't all that good of an idea. It's very slow. But substr is better than chop.. benchmarks included.. `Benchmark: timing 100000 iterations of chop, math, regex, substr... chop: 6 wallclock secs ( 4.92 usr + 0.03 sys = 4.95 CPU) @ 202 +02.02/s (n=100000) math: 2 wallclock secs ( 1.07 usr + 0.02 sys = 1.09 CPU) @ 917 +43.12/s (n=100000) regex: 25 wallclock secs (17.40 usr + 0.32 sys = 17.72 CPU) @ 56 +43.34/s (n=100000) substr: 2 wallclock secs ( 1.99 usr + 0.03 sys = 2.02 CPU) @ 495 +04.95/s (n=100000)` [download] Doing the math is still the best option..	[reply] [d/l]

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Re: Re: Re: Help with decimals
by rchiav (Deacon) on Jul 31, 2001 at 01:45 UTC

Benchmark: timing 100000 iterations of chop, math, regex, substr...
      chop:  6 wallclock secs ( 4.92 usr +  0.03 sys = 4.95 CPU) @ 202
+02.02/s (n=100000)
      math:  2 wallclock secs ( 1.07 usr +  0.02 sys = 1.09 CPU) @ 917
+43.12/s (n=100000)
     regex: 25 wallclock secs (17.40 usr +  0.32 sys = 17.72 CPU) @ 56
+43.34/s (n=100000)
    substr:  2 wallclock secs ( 1.99 usr +  0.03 sys = 2.02 CPU) @ 495
+04.95/s (n=100000)
[download]

[reply]
[d/l]