1Units(3) User Contributed Perl Documentation Units(3)
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6 Math::Calc::Units - Human-readable unit-aware calculator
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9 use Math::Calc::Units qw(calc readable convert equal);
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11 print "It will take ".calc("10MB/(384Kbps)")." to download\n";
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13 my @alternative_descriptions = readable("10MB/(384Kbps)");
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15 print "A week is ".convert("1 week", "seconds")." long\n";
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17 if (equal("$rate bytes / sec", "1 MB/sec")) { ... };
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20 "Math::Calc::Units" is a simple calculator that keeps track of units.
21 It currently handles combinations of byte sizes and duration only,
22 although adding any other multiplicative types is easy. Any unknown
23 type is treated as a unique user type (with some effort to map English
24 plurals to their singular forms).
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26 The primary intended use is via the "ucalc" script that prints out all
27 of the "readable" variants of a value. For example, "3 bytes" will only
28 produce "3 byte", but "3 byte / sec" produces the original along with
29 "180 byte / minute", "10.55 kilobyte / hour", etc.
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31 The "Math::Calc::Units" interface only provides for string-based
32 computations, which could result in a large loss of precision for some
33 applications. If you need the exact result, you may pass in an extra
34 parameter 'exact' to "calc" or "convert", causing them to return a
35 2-element list containing the numerical result and a string describing
36 the units of that result:
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38 my ($value, $units) = convert("10MB/sec", "GB/day");
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40 (In scalar context, they just return the numeric value.)
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42 Examples of use
43 · Estimate transmission rates (e.g., 10MB at 384 kilobit/sec)
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45 · Estimate performance characteristics (e.g., disk I/O rates)
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47 · Figure out how long something will take to complete
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49 I tend to work on performance-sensitive code that involves a lot of
50 network and disk traffic, so I wrote this tool after I became very sick
51 of constantly converting KB/sec to GB/day when trying to figure out how
52 long a run is going to take, or what the theoretical maximum
53 performance would be if we were 100% disk bound. Now I can't live
54 without it.
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56 Contraindications
57 If you are just trying to convert from one unit to another, you'll
58 probably be better off with "Math::Units" or "Convert::Units". This
59 module really only makes sense when you're converting to and from
60 human-readable values.
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63 Steve Fink <sfink@cpan.org>
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66 ucalc, Math::Units, Convert::Units.
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70perl v5.28.1 2009-08-04 Units(3)