#*****************************************************************************
# units.dat, the units data file, version 0.6.0
#
# ConvertAll, a units conversion programme
# Copyright (C) 2014, Douglas W. Bell
#
# This is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License, Version 2.  This programme is
# distributed in the hope that it will be useful, but WITTHOUT ANY WARRANTY.
#*****************************************************************************
#
# Units are defined by an optional quantity and an equivalent unit or unit
# combination.  A python expression may be used for the quantity, but is
# resticted to using only the following operators: *, /, +, -, **, (, ).
# Beware of integer division truncation: be sure to use a float for at
# least one of the values.
#
# The unit type must be placed in square brackets before a set of units.
# The first comment after the equivalent unit will be put in parenthesis after
# the unit name (usually used to give the full name of an abbreviated unit).
# The next comment will be used in the programme list's comment column;
# later comments and full line comments are ignored.
#
# Non-linear units are indicated with an equivalent unit in square brackets,
# followed by either equations or equivalency lists for the definition.
# For equations, two are given, separated by a ';'.  Both are functions of
# "x", the first going from the unit to the equivalent unit and the second
# one in reverse.  Any valid Python expression returning a float (including 
# the functions in the math module) should work.  The equivalency list is a 
# python list of tuples giving points for linear interpolation.
#
# All units must reduce to primitive units, which are indicated by an
# equivalent unit starting with '!'.  A special "unitless" primitve unit
# (usualty called "unit") has '!!' for an equivalent unit.  Circular references
# must also be avoided.
#
# Primitive units:  kg, m, s, K, A, mol, cd, rad, sr, bit, unit
#
##############################################################################

#
# mass units
#
[masse]
kg                = !                  # kilogramme
kilogramme          = kg
key               = kg                 # # jargon de drogue
hectogramme         = 100 gramme
decagramme          = 10 gramme
gramme              = 0.001 kg
g                 = gramme               # gramme
decigramme          = 0.1 gramme
centigramme         = 0.01 gramme
milligramme         = 0.001 gramme
mg                = milligramme          # milligramme
microgramme         = 0.001 mg
tonne             = 1000 kg            # # metriqu
tonne metrique        = tonne
megagramme          = tonne
kilotonne         = 1000 tonne         # # metrique
gigagramme          = 1e9 gramme
teragramme          = 1e12 gramme
carat             = 0.2 gramme
ct                = carat              # carat
amu               = 1.66053873e-27 kg  # masse atomique
masse atomique  = amu
livre             = 0.45359237 kg
lb                = livre              # livres
lbm               = livre              # livres
once             = 1/16.0 livre
oz                = once              # once
lid               = once              # # jargon de drogue
livre troy        = 5760 grain
lb troy           = livre troy         # livre troy
once troy        = 1/12.0 lb troy
oz troy           = once troy         # once troy
ton               = 2000 lb            # # impériale
kiloton           = 1000 ton           # # impériale
slug              = lbf*s^2/ft
stone             = 14 lb
grain             = 1/7000.0 lb
pennyweight       = 24 grain
masse solaire        = 1.9891e30 kg


#
# length / distance units
#
[longueur]
m                    = !              # mètre
mètre                = m
decimètre            = 0.1 m
cm                   = 0.01 m         # centimètre
centimètre           = cm
mm                   = 0.001 m        # millimètre
millimètre           = mm
micromètre           = 1e-6 m
micron               = micromètre
nanomètre            = 1e-9 m
nm                   = nanomètre      # nanomètre
decamètre            = 10 m
hectomètre           = 100 m
km                   = 1000 m         # kilomètre
kilomètre            = km
megamètre            = 1000 km
angstrom             = 1e-10 m
fermi                = 1e-15 m        # # grandeur nucléaire
pouce                 = 2.54 cm
in                   = pouce         # pouce
inches               = pouce
mil                  = 0.001 pouce
microinch            = 1e-6 pouce
microinches          = microinch
pied                 = 12 pouce
ft                   = pied           # pied
feet                 = pied
pied US survey       = 1200/3937.0 m
verge                 = 3 ft
yd                   = verge           # verge
mile                 = 5280 ft
mi                   = mile           # mille
nautical mile        = 1852 m
nmi                  = nautical mile  # mille nautique
league               = 3 mile
chain                = 66 ft
brasse               = 6 ft
fm		     = brasse
perche                  = 5.5 verge
furlong              = 40 perche
main                 = 4 pouce
cubit                = 21.8 pouce      # # coudée biblique
point                = 1/72.0 pouce      # # point de caractère
pica                 = 12 point
calibre              = 1.0 pouce       # # calibre d'une arme
terrain de football  = 100 yd
marathon             = 46145 yd
mille suedois          = 10 km
ua                   = 1.49597870691e11 m   # unité astronomique
unite astronomique    = ua
annee lumiere           = 365.25 vitesse lumiere * jour
minute lumiere         = vitesse lumiere * min
seconde lumiere        = vitesse lumiere * s
parsec               = 3.0856775813e16 m
kiloparsec           = 1000 parsec
megaparsec           = 1000 kiloparsec
screw size           = [in] 0.013*x + 0.06 ; (x - 0.06) / 0.013 \
                       # # Diamètre unifié, non linéaire
AWG                  = [in] 92.0**((36-x)/39.0)/200.0 ; \
                       36 - 39.0*log(200.0*x)/log(92.0) \
                       # Diamètre de câble électrique \
                       # utilisé -1, -2 for 00, 000; non linéaire
American Wire Gauge  = [in] 92.0**((36-x)/39.0)/200.0 ; \
                       36 - 39.0*log(200.0*x)/log(92.0) \
                       #  # utilisé -1, -2 for 00, 000; non linéaire
standard gauge       = [in] [(-5, .448350), (1, .269010), (14, .0747250), \
                       (16, .0597800), (17, .0538020), (20, .0358680), \
                       (26, .0179340), (31, .0104615), (36, .00672525), \
                       (38, .00597800)] # acier \
                       # Diamètre standard, non linéaire
zinc gauge           = [in] [(1, .002), (10, .02), (15, .04), (19, .06), \
                       (23, .1), (24, .125), (27, .5), (28, 1)]  \
                       # # épaisseur de la feuille de métal, non linéaire
taille bague            = [in] 0.1018*x + 1.4216 ; (x - 1.4216) / 0.1018  \
                       # # Taille américaine, circ., non linéaire
grandeur soulier homme       = [in] x/3.0 + 7 + 1/3.0 ; (x - 7 - 1/3.0) * 3 \
                       # # Taille américainre, non linéaire
grandeur soulier femme     = [in] x/3.0 + 6 + 5/6.0 ; (x - 6 - 5/6.0) * 3 \
                       # # Taille américainre, non linéaire


#
# unités de temps
#
[temps]
s             = !                 # seconde
sec           = s                 # seconde
seconde        = s
ms            = 0.001 s           # milliseconde
milliseconde   = ms
microseconde   = 1e-6 s
ns            = 1e-9 s            # nanoseconde
nanoseconde    = ns
minute        = 60 s
min           = minute            # minute
heure          = 60 min
hr            = heure              # heure
bell          = 30 min            #  # définition nautique
watch         = 4 heure
watches       = watch
jour           = 24 hr
semaine          = 7 jour
wk            = semaine              # semaine
fortnight     = 14 jour
mois         = 1/12.0 annee
annee          = 365.242198781 jour
yr            = annee              # année
annee calendrier = 365 jour
decennie        = 10 annee
siecle       = 100 annee
siecles     = siecle
millenaire    = 1000 annee
millennia     = millenaire
[horaire]
man heure      = 168/40.0 heure
man week      = 40 man heure
man month     = 1/12.0 man year
man year      = 52 man week


#
# température
#
[temperature]
K                 = !     # Kelvin
Kelvin            = K
deg K             = K     # Kelvin
degree Kelvin     = K

C                 = [K] x + 273.15 ; x - 273.15  # Celsius  # non linéaire
Celsius           = [K] x + 273.15 ; x - 273.15  #          # non linéaire
deg C             = [K] x + 273.15 ; x - 273.15  # Celsius  # non linéaire
degre Celsius    = [K] x + 273.15 ; x - 273.15  #          # non linéaire

R                 = 5/9.0 K     # Rankine
Rankine           = R
deg R             = R           # Rankine
F                 = [R] x + 459.67 ; x - 459.67  # Fahrenheit  # non linéaire
Fahrenheit        = [R] x + 459.67 ; x - 459.67  #             # non linéaire
deg F             = [R] x + 459.67 ; x - 459.67  # Fahrenheit  # non linéaire
degree Fahrenheit = [R] x + 459.67 ; x - 459.67  #             # non linéaire

[temp. diff.]
C deg             = K        # degré Celsius
Celsius degree    = C deg
F deg             = R        # degré Fahrenheit
Fahrenheit degree = F deg


#
# electrical units
##
[intensité du courrant]
A              = !              # ampère
ampère         = A
amp            = A
milliampère    = 0.001 A
milliamp       = milliampère
mA             = milliampère    # milliamèpre
microampère    = 0.001 mA
kiloampère     = 1000 A
kA             = kiloampère     # kiloampère
[charge]
coulomb        = A*s
amp heure       = A*hr
mAh            = 0.001 amp heure # miliampère-heure
milliamp heure  = mAh
[voltage]
volt           = W/A
V              = volt           # volt
millivolt      = 0.001 volt
mV             = millivolt      # millivolt
kilovolt       = 1000 volt
kV             = kilovolt       # kilovolt
[resistance]
ohm            = V/A
milliohm       = 0.001 ohm
microhm        = 0.001 milliohm
kilohm         = 1000 ohm
[conductance]
siemens        = A/V
[capacité]
farad          = coulomb/V
millifarad     = 0.001 farad
microfarad     = 0.001 millifarad
nanofarad      = 1e-9 farad
picofarad      = 1e-12 farad
[flux mag.]
weber          = V*s
Wb             = weber          # weber
maxwell        = 1e-8 Wb
[inductance]
henry          = Wb/A
H              = henry          # henry
millihenry     = 0.001 henry
mH             = millihenry     # millihenry
microhenry     = 0.001 mH
[flux de densité]
tesla          = Wb/m^2
T              = tesla          # tesla
gauss          = maxwell/cm^2


#
# molecular units
#
[quantité moléculaire]
mol          = !           # mole       # masse molaire
mole         = mol         #            # masse molaire
gramme mole    = mol
kilomole     = 1000 mol
kmol         = kilomole    # kilomole
livre mole   = mol*lbm/gramme
lbmol        = livre mole  # mole-livres
[nombre d'atomes]
avogadro     = gramme/(amu*mol)


#
# Illumination units
#
[lum. intens.]
cd          = !          # candela
candela     = cd

[flux lumineux]
lumen        = cd * sr
lm           = lumen     # lumen

[illuminance]
lux          = lumen/m^2
footcandle   = lumen/ft^2
mètrecandle  = lumen/m^2

[luminance]
lambert      = cd/(pi*cm^2)
millilambert = 0.001 lambert
footlambert  = cd/(pi*ft^2)


#
# angular units
#
[angle]
radian      = !
rad         = radian         # radian
cercle      = 2 pi*radian
tour        = cercle
revolution  = cercle
rev         = revolution     # tour
degre      = 1/360.0 cercle
deg         = degre         # degré
arc min     = 1/60.0 degre  # minute
arc minute  = arc min
min arc     = arc min        # minute
minute arc  = arc min
arc sec     = 1/60.0 arc min # seconde
arc seconde  = arc sec
sec arc     = arc sec        # seconde
seconde arc  = arc sec
quadrant    = 1/4.0 cercle
right angle = quadrant
gradian     = 0.01 quadrant


#
# solid angle units
#
[angle dans les solides]
sr         = !      # stéradian
steradian  = sr
sphère     = 4 pi*sr
hemisphère = 1/2.0 sphère


#
# information units
#
[données informatiques]
bit              = !
kilobit          = 1000 bit          #                  # en base 10
megabit          = 1000 kilobit      #                  # en base 10
byte             = 8 bit
B                = byte              # byte
kilobyte         = 1024 byte         #                  # en binaire
kB               = kilobyte          # kilobyte         # en binaire
megabyte         = 1024 kB           #                  # en binaire
MB               = megabyte          # megabyte         # en binaire
gigabyte         = 1024 MB           #                  # en binaire
GB               = gigabyte          # gigabyte         # en binaire
terabyte         = 1024 GB           #                  # en binaire
TB               = terabyte          # terabyte         # en binaire
petabyte         = 1024 TB           #                  # en binaire
PB               = petabyte          # petabyte         # en binaire

kilobyte IEC std = 1000 byte         #                  # en base 10
kB IEC std       = kilobyte IEC std  # kilobyte         # en base 10
megabyte IEC std = 1000 kB IEC std   #                  # en base 10
MB IEC std       = megabyte IEC std  # megabyte         # en base 10
gigabyte IEC std = 1000 MB IEC std   #                  # en base 10
GB IEC std       = gigabyte IEC std  # gigabyte         # en base 10
terabyte IEC std = 1000 GB IEC std   #                  # en base 10
TB IEC std       = terabyte IEC std  # terabyte         # en base 10
petabyte IEC std = 1000 TB IEC std   #                  # en base 10
PB IEC std       = petabyte IEC std  # petabyte         # en base 10

kibibyte         = 1024 byte
KiB              = kibibyte          # kibibyte
mebibyte         = 1024 KiB
MiB              = mebibyte          # mebibyte
gibibyte         = 1024 MiB
GiB              = gibibyte          # gibibyte
tebibyte         = 1024 GiB
TiB              = tebibyte          # tebibyte
pebibyte         = 1024 TiB
PiB              = pebibyte          # pebibyte

[transfert de donnée]
bps              = bit/sec           # bits / seconde
kbps             = 1000 bps          # kilobits / sec.  # en base 10


#
# Unitless numbers
#
[quantitée]
unite               = !!
1                  = unite            # unité
pi                 = 3.14159265358979323846 unite
paire               = 2 unite
tour du chapeau          = 3 unite          # # sports
douzaine              = 12 unite
doz                = douzaine           # douzaine
trieze à la douzaine       = 13 unite
score              = 20 unite
grosse              = 144 unite
grande grosse        = 12 grosse
ream               = 500 unite
pourcent            = 0.01 unite
%                  = pourcent
millieme               = 0.001 unite
[taux d'intérêt]
APR                = [unite] log(1 + x/100) ;  (exp(x) - 1)*100 \
                     # annual % rate # based on continuous comlivreing
[concentration]
proof              = 1/200.0 unite    # # contenant d'alcool
ppm                = 1e-6 unite       # parties par million
partie par million  = ppm
ppb                = 1e-9 unite       # parties par milliard
partie par milliard  = ppb
ppt                = 1e-12 unite      # parties par billion
partie par billion = ppt
karat              = 1/24.0 unite     # # pureté de l'or
carat d'or         = karat           # # pureté de l'or


#
# force units
#
[force]
newton         = kg*m/s^2
N              = newton          # newton
dekanewton     = 10 newton
kilonewton     = 1000 N
kN             = kilonewton      # kilonewton
meganewton     = 1000 kN
millinewton    = 0.001 N
dyne           = cm*g/s^2
kg force       = kg * acceleration gravitationnelle    # kilogramme-force
kgf            = kg force        # kilogramme-force
kilogramme force = kg force
gramme force     = g * acceleration gravitationnelle
livre force    = lbm * acceleration gravitationnelle
lbf            = livre force     # livres-force
tonne force      = tonne * acceleration gravitationnelle
once force    = once * acceleration gravitationnelle
ozf            = once force     # once-force


#
# area units
#
[aire]
barn          = 1e-28 m^2       # # physique des particules
are           = 100 m^2
decare        = 10 are
dekare        = 10 are
hectare       = 100 are
acre          = 10 chain^2
section       = mile^2
township      = 36 section
homestead     = 160 acre
rai           = 1600 m^2        # # Thai
ngaan         = 400 m^2         # # Thai
circular pouce = 1/4.0 pi*in^2   # # cercle d'un pouce de surface
circular mil  = 1/4.0 pi*mil^2  # # cercle d'un mille de surface


#
# volume units
#
[volume]
cc                   = cm^3                 # centimètre cube
centimètre cube     = cc
litre                = 1000 cc
l                    = litre                # litre
liter                = litre
decilitre            = 0.1 litre
centilitre           = 0.01 litre
millilitre           = cc
ml                   = millilitre           # millilitre
dekalitre            = 10 litre
hectolitre           = 100 litre
kilolitre            = 1000 litre
kl                   = kilolitre            # kilolitre
megalitre            = 1000 kilolitre
gallon               = 231 in^3             #             # US liquide
gal                  = gallon               # gallon      # US liquide
quart                = 1/4.0 gallon         #             # US liquide
qt                   = quart                # litre       # US liquide
pint                 = 1/2.0 quart          #             # US liquide
pt                   = pint                 # pinte        # US liquide
once liquide          = 1/16.0 pint          #             # US
fl oz                = once liquide          # once liquide # US
impérial gallon      = 4.54609 litre
imp gal              = impérial gallon      # gallon impérial
gallon impérial      = impérial gallon
impérial quart       = 1/4.0 imp gal
imp qt               = impérial quart       # litre impérial
quart impérial       = impérial quart
impérial pint        = 1/8.0 imp gal
imp pt               = impérial pint        # pinte impériale
pint impérial        = impérial pint
once liquide impériale = 1/160.0 imp gal
imp fl oz            = once liquide impériale # once liquide impériale
tasse                  = 8 fl oz
cuillier a table           = 1/16.0 tasse
c-a-t                 = cuillier a table	# cuillère à table
cuillier a the             = 1/3.0 c-a-t
tsp                  = cuillier a the             # cuillère à thé
baril               = 42 gallon
bbl                  = baril               # baril
shot                 = 1.5 fl oz
fifth                = 1/5.0 gallon         #             # alcool
bouteille de vin          = 750 ml
magnum               = 1.5 litre            #             # alcool
tonneau                  = 15.5 gallon          #             # bière
hogshead wine        = 63 gal
hogshead beer        = 54 gal
bushel               = 2150.42 in^3
peck                 = 1/4.0 bushel
cord                 = 128 ft^3
board foot           = ft^2*in
board feet           = board foot


#
# velocity units
#
[vitesse]
noeud        = nmi/hr
kt          = noeud             # noeud
vitesse lumiere = 2.99792458e8 m/s
mph         = mi/hr            # milles/heure
kph         = km/hr            # kilomètres/heure
mach        = 340.29 m/s       # # mur du son
[vitesse de rotation]
rpm         = tour/min          # tour/min
rps         = tour/sec          # tour/sec


#
# flow rate units
#
[flux de fluide]
gph         = gal/hr           # gallons/heure
gpm         = gal/min          # gallons/minute
cfs         = ft^3/sec         # pieds cubes/seconde
cfm         = ft^3/min         # pieds cubes/minute
lpm         = l/min            # litre/min
[flux de gaz]
sccm        = atm*cc/min       # TPN cc/min      # pression * flux
sccs        = atm*cc/sec       # TPN cc/sec      # pression * flux
slpm        = atm*l/min        # TPN litre/min   # pression * flux
slph        = atm*l/hr         # TPN litre/heure  # pression * flux
scfh        = atm*ft^3/heure    # TPN pied cube/heure  # pression * flux
scfm        = atm*ft^3/min     # TPN pied cube/min   # pression * flux


#
# pressure units
#
[pression]
Pa                    = N/m^2                    # Pascal
pascal                = Pa
hPa                   = 100 Pa                   # hectoPascal
hectopascal           = hPa
kPa                   = 1000 Pa                  # kiloPascal
kilopascal            = kPa
MPa                   = 1000 kPa                 # megaPascal
megapascal            = MPa
GPa                   = 1000 MPa                 # gigaPascal
gigapascal            = GPa
atm                   = 101325 Pa                # atmosphère
atmosphère            = atm
bar                   = 1e5 Pa
mbar                  = 0.001 bar                # millibar
millibar              = mbar
microbar              = 0.001 mbar
decibar               = 0.1 bar
kilobar               = 1000 bar
megabar               = 1000 kilobar
mm Hg                 = mm*densité Hg*acceleration gravitationnelle
millimètre de Hg      = mm Hg
torr                  = mm Hg
in Hg                 = in*densité Hg*acceleration gravitationnelle    # mm de Hg
pouce de Hg            = in Hg
m water               = m*densité eau*acceleration gravitationnelle  # mètre de H2O
m H2O                 = m water                  # mètre de H2O
metre de water        = m water
in water              = in*densité eau*acceleration gravitationnelle # pouce de H2O
in H2O                = in water                 # pouce de H2O
inch of water         = in water
ft water              = ft*densité eau*acceleration gravitationnelle # pied de H2O
ft H2O                = ft water                 # pied de H20
feet of water         = ft water
foot of head          = ft water
ft hd                 = ft water                 # foot of head
psi                   = lbf/in^2                 # livre / pouce carré
livre par pouce carre    = psi
ksi                   = 1000 psi                 # 1000 lb / pouce carré


#
# density units
#
[densite]
densité eau         = gramme/cm^3
densité eau salee     = 1.025 gramme/cm^3
densité Hg            = 13.5950981 gramme/cm^3
densité air           = 1.293 kg/m^3          # # a TPN
densité acier         = 0.283 lb/in^3         # # acier carbone
densité aluminum      = 0.098 lb/in^3
densité zinc          = 0.230 lb/in^3
densité cuivre-zinc         = 0.310 lb/in^3         # # 80Cu-20Zn
densité cuivre        = 0.295 lb/in^3
densité fonte          = 0.260 lb/in^3         # # fonte
densité nickel        = 0.308 lb/in^3
densité tin           = 0.275 lb/in^3
densité titane     = 0.170 lb/in^3
densité argent        = 0.379 lb/in^3
densité nylon         = 0.045 lb/in^3
densité polycarbonate = 0.045 lb/in^3


#
# energy units
#
[energie]
joule                = N*m
J                    = joule             # joule
kilojoule            = 1000 joule
kJ                   = kilojoule         # kilojoule
megajoule            = 1000 kilojoule
gigajoule            = 1000 megajoule
millijoule           = 0.001 joule
mJ                   = millijoule        # millijoule
calorie              = 4.1868 J
cal                  = calorie           # calorie
kilocalorie          = 1000 cal
kcal                 = kilocalorie       # kilocalorie
calorie food         = kilocalorie
thermie              = 1000 kcal
Btu                  = cal*lb*R/(g*K)    # British thermal unit
British thermal unit = Btu
therm                = 100000 Btu
erg                  = cm*dyne
electronvolt         = 1.602176462e-19 J
eV                   = electronvolt      # electronvolt
kWh                  = kW*heure           # kilowatt-heure
kilowatt heure        = kWh
tonne TNT              = 4.184e9 J


#
# power units
#
[puissance]
watt              = J/s
W                 = watt            # watt
kilowatt          = 1000 W
kW                = kilowatt        # kilowatt
megawatt          = 1000 kW
MW                = megawatt        # megawatt
gigawatt          = 1000 MW
GW                = gigawatt        # gigawatt
milliwatt         = 0.001 W
horsepower        = 550 ft*lbf/sec
hp                = horsepower      # chevaux-vapeur
horsepower metrique = 75 kgf*m/s


#
# frequency
#
[frequence]
hertz       = unite/sec
Hz          = hertz      # hertz
millihertz  = 0.001 Hz
kilohertz   = 1000 Hz
kHz         = kilohertz  # kilohertz
megahertz   = 1000 kHz
MHz         = megahertz  # megahertz
gigahertz   = 1000 MHz
GHz         = gigahertz  # gigahertz


#
# radioactivity
#
[radioactivite]
becquerel       = unite/sec
Bq              = becquerel     # becquerel
curie           = 3.7e10 Bq
millicurie      = 0.001 curie
roentgen        = 2.58e-4 coulomb/kg
[dose de radiation]
gray            = J/kg
Gy              = gray          # gray
rad. abs. dose  = 0.01 Gy       # # rad commun
sievert         = J/kg          # # equiv. dose
millisievert    = 0.001 sievert # # equiv. dose
Sv              = sievert       # sievert # equiv. dose
rem             = 0.01 Sv       # # roentgen equiv mammal
millirem        = 0.001 rem     # # roentgen equiv mammal


#
# viscosity
#
[viscosite]
poise        = g/(cm*s)
P            = poise       # poise
centipoise   = 0.01 poise
cP           = centipoise  # centipoise

[viscosite]
stokes       = cm^2/s
St           = stokes      # stokes
centistokes  = 0.01 stokes
cSt          = centistokes # centistokes


#
# misc. units
#
[acceleration]
acceleration gravitationnelle                = 9.80665 m/s^2
[constante]
constante de gravite       = 6.673e-11 N*m^2/kg^2
constante des gaz           = 8.314472 J/(mol*K)     # R
[consommation d'essence]
mpg                    = mi/gal               # milles/gallon
mpg imp                = mi/gallon impérial   # milles/gallon imp.
litre par 100 km       = [mpg] 3.785411784 / (x * 0.01609344) ; \
                         3.785411784 / (x * 0.01609344) # # non linéaire

