[src/trunk]: src/usr.bin/units Some more corrections/additions in units.lib:

[dholland <dholland%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f9007911e750
branches:  trunk
changeset: 371989:f9007911e750
user:      dholland <dholland%NetBSD.org@localhost>
date:      Mon Oct 24 05:52:48 2022 +0000

description:
Some more corrections/additions in units.lib:

1. cables; US cables are 720 ft, but international cables are 1/10
nautical mile and UK Admiralty cables are 1/10 of 1853.2 meters
instead of 1852 meters. Make "cable" refer to the international
definition, and add "uscable" and "admiraltycable".

2. rods and chains. US rods and chains and furlongs are defined in
terms of US survey feet, not international feet. Since the US is
apparently working on retiring survey feet, it seems like the best way
forward on this is to define two sets of these units, one prefixed
with "us". Also since this file was inconsistent about using "survey"
vs. "surveyors", fill in more duplicates.

Furthermore, Gunter's rods and chains and links are as best I can tell
the same as the international ones, so since we already have
"gunterschain" add "guntersrod" and "gunterslink".

3. If we're going to make pf a special abbreviation for picofarad,
it's reasonable to make uf a special abbreviation for microfarad, and
if we're going to define "meg" for "megabyte" we should also have
"gig".

4. A "franklin" _is_ a statcoulomb, not an approximation of one.

5. "jewel" has two Es.

diffstat:

 usr.bin/units/units.lib |  84 +++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 68 insertions(+), 16 deletions(-)

diffs (160 lines):

diff -r 8ac08a675d9a -r f9007911e750 usr.bin/units/units.lib
--- a/usr.bin/units/units.lib   Mon Oct 24 05:04:50 2022 +0000
+++ b/usr.bin/units/units.lib   Mon Oct 24 05:52:48 2022 +0000
@@ -1,4 +1,4 @@
-/      $NetBSD: units.lib,v 1.28 2022/10/24 05:04:50 dholland Exp $
+/      $NetBSD: units.lib,v 1.29 2022/10/24 05:52:48 dholland Exp $
 
 / primitive units
 
@@ -104,7 +104,7 @@
 degree                 1|180 pi-radian
 circle                 2 pi-radian
 turn                   2 pi-radian
-revolution                     turn
+revolution             turn
 rev                    turn
 grade                  .9 degree
 arcdeg                 1 degree
@@ -291,33 +291,82 @@
 mil                    1e-3 in
 
 / nautical
+/
 / Historically, the nautical mile was 6080 feet (6080.2 in England)
 / but was changed to 1852 meters (6076 feet and change) in the 20th
 / century with varying dates of adoption around the world.
 / https://en.wikipedia.org/wiki/Nautical_mile
+/
+/ The US cable is 720 feet. The international cable is 1/10 nautical
+/ mile, which is substantially shorter. The UK Admiralty cable is
+/ apparently 1/10 of a historical Admiralty nautical mile, which is
+/ 1853.2 instead of 1852 meters. These definitions date from the 20th
+/ century. Historically, a cable was 100 fathoms, but the fathom
+/ hadn't yet been fixed at 6 feet, so cables weren't a fixed length
+/ either.
+/ https://en.wikipedia.org/wiki/Cable_(unit)
+/
 fathom                 6 ft
 nmile                  1852 m
 nauticalmile           nmile
 marineleague           3 nmile
-cable                  720 ft
+cable                  1|10 nmile
+uscable                        720 ft
+admiraltycable         185.32 m
 
 / surveying
 /
 / The US survey foot is defined as 1200/3937 meters, as opposed to the
 / ordinary international foot, which is 0.3048 meter (that's exactly
-/ 2.54 cm to the inch as defined above.)
+/ 2.54 cm to the inch as defined above.) These differ slightly.
 / https://en.wikipedia.org/wiki/Foot_(unit)
-rod                    5.5 yd
-rd                     rod
-perch                  rd
-pole                   rd
-chain                  66 ft
-link                   66|100 ft
-furlong                        220 yd
+/
+/ In the US, rods, chains, and furlongs are defined in terms of survey
+/ feet, though the Wikipedia page on furlongs claims without citation
+/ that some states use one definition and some the other. However, it
+/ appears that as of 2022 this definition is on the way out, and other
+/ jurisdictions define these units (to the extent they're used at all)
+/ in terms of the international foot.
+/ https://en.wikipedia.org/wiki/Rod_(unit)
+/ https://en.wikipedia.org/wiki/Furlong_(unit)
+/
+/ Consequently we'll make two sets of definitions and prefix the
+/ variant US ones with "us".
+/
+/ Since historically this file defined "surveyfoot" and "surveyyard"
+/ but "surveyorschain" and "surveyorslink", we will now end up with
+/ several sets for consistency.
+/
 surveyfoot             1200|3937 meter
 surveyyard             3 surveyfoot
-surveyorschain         66 ft
-surveyorslink          66|100 ft
+
+rod                    5.5 yard
+rd                     rod
+perch                  rod
+pole                   rod
+chain                  66 foot
+link                   1|100 chain
+furlong                        220 yard
+
+usrod                  5.5 surveyyard
+usperch                        usrod
+uspole                 usrod
+uschain                        66 surveyfoot
+uslink                 1|100 uschain
+usfurlong              220 surveyyard
+
+surveyorsfoot          surveyfoot
+surveyorsyard          surveyyard
+surveyorsrod           usrod
+surveyorschain         uschain
+surveyorslink          uslink
+
+/ These are the same as the basic ones based on the international foot.
+/ https://en.wikipedia.org/wiki/Gunter's_chain
+/ https://en.wikipedia.org/wiki/Imperial_units
+guntersrod             rod
+gunterschain           chain
+gunterslink            link
 
 / typographical
 pica                   1|6 in
@@ -363,7 +412,6 @@
 geographicalmile       1852 m
 engineerschain         100 ft
 engineerslink          100|100 ft
-gunterschain           22 yd
 
 / note that while caliber is technically a unit, caliber sizes for ammunition
 / are usually short names for more complicated specifications.
@@ -603,13 +651,13 @@
 
 / special-case abbreviations
 mh                     millihenry
+uf                     microfarad
 pf                     picofarad
 
 / other
 biot                   10 amp
 debye                  3.336e-30 coul-m
 faraday                        9.652e+4 coul
-franklin               3.33564e-10 coul
 gamma                  1e-9 weber/m2
 gauss                  1e-4 weber/m2
 gilbert                        7.95775e-1 amp
@@ -625,6 +673,9 @@
 statvolt               2.99792458e2 volt
 statcoulomb            statcoul
 statampere             statamp
+/ franklin is an alternate name for statcoulomb
+/ https://en.wikipedia.org/wiki/Franklin_(unit)
+franklin               statcoul
 
 / ////////////////////////////////////////////////////////////
 / more energy
@@ -794,6 +845,7 @@
 megabyte               1024 kbyte
 gigabyte               1024 megabyte
 meg                    megabyte
+gig                    gigabyte
 terabyte               1024 gigabyte
 petabyte               1024 terabyte
 
@@ -845,5 +897,5 @@
 linenyarncount         900 ft/pound
 worstedyarncount       1680 ft/pound
 metricyarncount                meter/gram
-jewlerspoint           2 milligram
+jewelerspoint          2 milligram