Unit functions

Contents

Interface Function Documentation Other Documentation Page Comments

Interface

#include <codecogs/units/convert.h>

using namespace Units;

	enum	units Measurement units, including imperial and SI units
	double	convert (double number, units from_unit, units to_unit) Converts numbers using enumerated unit types
	int	recogniseUnit (const char* unit, float &hitrate) This function tries to find the closest match to the specified unit.
	int	recognisePower (char* &unit) Recognises the power token in a text string of a unit
	double	convert (double number, char* from_unitstr, char* to_unitstr) Converts a number from one unit to another

Function Documentation

Converts numbers from one unit to another. This module acts as a unit converter, converting approximately 150 different units (see below).

This module is similar to the EXCEL convert function, only considerably smarter. Converts a number from one measurement system to another. For example, convert can translate a distance in miles to meters. There is a check that the requested input and output units are compatable i.e. it will not allow a length to be converted into a pressure.

Example 1:

#include <iostream>
#include <codecogs/units/convert.h>
using namespace Units;
int main()
{
  std::cout << "convert(10.2,unit_m, unit_ft)=" <<convert(10.2,unit_m, unit_ft);
  std::cout << "convert(123, unit_W, unit_HP)=" <<convert(123, unit_W, unit_hp);
 
  return 0;
}

Output:

convert(10.2,unit_m, unit_ft)= 33.46456693
  convert(123, unit_W, unit_HP)= 0.013678405

Note:

Conversion between incompatible types will throw an error

References:

http://www.unc.edu/~rowlett/units/index.html

Parameters:

number	the value in from_unit 's to convert
from_unit	an enumerated value of the initial measurement type
to_unit	an emuerated value of the output measurement type

Returns:

the value in the converted unit.

Authors:

realnero

This function attempts to recognise the unit within a character string. The function scans through a list of variable names and computes the percentage match. It returns the variable with the highest match, i.e. the closest unit to the string specified.

See:

Used by convert to recognises each of the two input strings.

Example 2:

#include <iostream>
#include <codecogs/units/convert.h>
 
int main()
{
   std::cout << "convert(10.2,\"meters\", \"feet\")=" << Units::convert(10.2,"meters", "feet");
   std::cout << "convert(123, \"W\", \"Horce power\")=" << Units::convert(123, "W", "Horce power");

   return 0;
}

Output:

convert(10.2,"meters", "feet")= 33.46456693
  convert(123, "W", "Horce power")= 0.013678405

Parameters:

unit	character string containing a possible measurement unit
hitrate	the computed accuracy of the match to a unit through this reference.

Authors:

Will Bateman and Nick Owens

Recognises the power token for SI units within in a text string

long token	short token	power
exa	E	18
peta	P	15
tera	T	12
giga	G	9r
mega	M	6
kilo	k	3
hecto	h	2
dekao	e	1
deci	d	-1
centi	c	-2
milli	m	-3
micro	u	-6
nano	n	-9
pico	p	-12
femto	f	-15
atto	a	-18

Parameters:

unit	pointer to a text string containing possible power part for an SI unit. If a power is idenitified within the string, this pointer is advanced so that it points to the start of the subsequent unit.

Returns:

the power of ten to which the SI unit is raised.

Recognised the units within two character strings and converts the given number from one unit ito another. This routine tries to find the optimal match by calculating the most likely set of units from given text strings. To improve the matching, it is important that the initial spelling of the unit is correct (first 3-4 characters). The importance of subsequent letters becomes increasingly irrelevent.

Note:

Conversion between incompatible types will return 0.

Parameters:

number	the value to convert
from_unitstr	an string value of the initial measurement type
to_unitstr	an string value of the output measurement type

Returns:

the value in the converted unit.

Other Documentation

The standard measurement units are:

Unit names	Alternate names / spellings	Abbreviation	Enumeration Code	Conversion Rate (relative to first unit)
Distance
Meter	metre	m	unit_m	1
Feet	Foot	ft	unit_ft	3.280839895
Furlongs	Furlong	fur	unit_fur	0.00497097
Inches	Inch	in	unit_in	39.37007874
Light years	Lightyears	ly	unit_ly	1.06E-16
Miles	Miles	mile	unit_mile	0.000621371
Nautical Miles	Nautical Mile	nmile	unit_nmile	0.000539957
Parsecs	Parsec	psc	unit_psc	3.24E-17
Yards	Yard	yd	unit_yd	1.093613298
Flow
Litres/second	Liters/second	l/s	unit_l_s	1
Feet3/hour	Foot3/hour	cu ft/hr	unit_ft3_hr	127.1328002
Feet3/minute	Foot3/minute	cu ft/min	unit_ft3_min	2.118880003
Feet3/second	Foot3/second	Cu ft/sec	unit_ft3_sec	0.035314667
Gallons (UK)/day	Gallon (UK)/day	gal/da (UK)	unit_gal_da_uk	19005.33469
Gallons (UK)/hour	Gallon (UK)/hour	gal/hr (UK)	unit_gal_hr_uk	791.8889455
Gallons (UK)/minute	Gallon (UK)/minute	gal/min (UK)	unit_gal_min_uk	13.19814909
Gallons (UK)/second	Gallon (UK)/second	gal/sec (UK)	unit_gal_sec_uk	0.219969152
Gallons/day	Gallon/day	gal/da	unit_gal_da	22824.46532
Gallons/hour	Gallon/hour	gal/hr	unit_gal_hr	951.0193885
Gallons/minute	Gallon/minute	gal/min	unit_gal_min	15.85032314
Gallons/second	Gallon/second	gal/sec	unit_gal_sec	0.264172052
Litres/day	Liters/day	l/da	unit_l_da	86400
Litres/hour	Liters/hour	l/hr	unit_l_hr	3600
Litres/minute	Liters/minute	l/min	unit_l_min	60
Meters3/day	Metres3/day	cu m/da	unit_m3_da	86.4
Meters3/hour	Metres3/hour	cu m/hr	unit_m3_hr	3.6
Meters3/minute	Metres3/minute	cu m/min	unit_m3_min	0.06
Meters3/second	Metres3/second	cu m/sec	unit_m3_sec	0.001
Ounces (UK)/hour	Ounce (UK)/hour	oz/hr (UK)	unit_oz_hr_uk	126702.2313
Ounces (UK)/minute	Ounce (UK)/minute	oz/hr (UK)	unit_oz_min_uk	2111.703855
Ounces (UK)/second	Ounce (UK)/second	oz/hr (UK)	unit_oz-hr_uk	35.19506424
Ounces/hour	Ounce/hour	oz/hr	unit_oz_hr	121730.4817
Ounces/minute	Ounce/minute	oz/min	unit_oz_min	2028.841362
Ounces/second	Ounce/second	oz/sec	unit_oz_sec	33.8140227
Yards3/hour	Yard3/hour	cu yd/hr	unit_yd3_hr	4.70862223
Yards3/minute	Yard3/minute	cu yd/min	unit_yd3_min	0.078477037
Yards3/second	Yard3/second	cu yd/sec	unit_yd3_sec	0.001307951
Density
Grams/Meter3	Grams/Metre3	g/cu m	unit_g_m3	1
Ounces/Gallon	Ounce/Gallon	Oz/gal	unit_Oz_gal	0.000133526
Pounds/Foot3	Pounds/Feet3	lb/cu ft	unit_lb_ft3	6.24E-05
Pounds/Inch3	Pound/Inch3	lb/cu in	unit_lb_in3	3.61E-08
Tons/Yard3	Tonne/Yard3	T/cu yd	unit_T_yd3	1.44E-06
Area
Meters2	Metres2	sq m	unit_m2	1
Acres	acre	a	unit_a	0.000247104
Feet2	foot2	sq ft	unit_ft2	10.76391042
Hectares	Hectare	ha	unit_ha	0.0001
Inches2	Inch2	sq in	unit_in2	1550.0031
Miles2	Mile2	sq mi	unit_mi2	3.86E-07
Yards2	Yard2	sq yd	unit_yd2	1.195990046
Angle
Radians	Radian	rad	unit_rad	1
Circles	Circle	cir	unit_cir	0.159154943
Degrees	Degree	deg	unit_deg	57.29577951
Grades	Grade	grd	unit_grd	63.66197724
Minutes	Minute	min (angle)	unit_min_angle	3437.746771
Octants	Octant	octant	unit_octant	1.273239545
Revolutions	Revolution	rev	unit_rev	0.159154943
Seconds	Second	sec	unit_sec_angle	206264.8062
Turns	Turn	trn	unit_trn	0.159154943
Quadrants	Quadrant	quad	unit_quad	0.636619772
Acceleration
Meters/sec2	Metres/sec2	m/sq sec	unit_m_sec2	1
Feet/sec2	foot/sec2	ft/sq sec	unit_ft_sec2	3.280839895
Free fall (g)	gravity	g (grav)	unit_grav	0.101971621
Inches/sec2	Inch/sec2	in/sq sec	unit_in_sec2	39.37007874
Speed
Meters/second	Metres/second	m/sec	unit_m_sec	1
Meters/minute	Metres/minute	m/min	unit_m_min	60
Meters/hour	Metres/hour	m/hr	unit_m_hr	3600
Feet/second	foot/second	ft/sec	unit_ft_sec	3.280839895
Feet/minute	foot/minute	ft/min	unit_ft_min	196.8503937
Feet/hour	foot/hour	ft/hr	unit_ft_hr	11811.02362
Knots	Knot	kt	unit_kt	1.943844492
Mach	Machs	Ma	unit_Ma	0.003016955
Miles/second	Mile/second	mi/sec	unit_mi_sec	0.000621371
Miles/minute	Mile/minute	mi/min	unit_mi_min	0.037282272
Miles/hour	Mile/hour	mph	unit_mph	2.236936292
Pressure
Pascals	Pascal	Pa	unit_Pa	1
Atmospheres	Atmosphere	atm	unit_atm	9.87E-06
Bars	Bar	bar	unit_bar	1.00E-05
Cm of Mercury	Cm Mercury	cmHg	unit_cmHg	0.000750062
Dynes/Centimeter2	Dynes/Centimetre2	dyn/sq cm	unit_dyn_cm2	10
Inches of Mercury	Inch of Mercury	in Hg	unit_inHg	0.0002953
Pounds/Foot2	Pounds/Feet2	lb/sq ft	unit_lb_ft2	0.020885434
Pounds/Inch2	Pound/Inches2	PSI	unit_PSI	0.000145038
Tons/Foot2	Tonnes/Feet2	T/sq ft	unit_T_ft2	1.04E-05
Tons/Inch2	Tonnes/Inch2	T/sq in	unit_T_in2	7.25E-08
Torrs		Torr	unit_Torr	0.007500617
Kilograms/Meter2	Kilograms/Metre2	kg/sq m	unit_kg_m2	0.101971621
Power
Watts	Watts	W	unit_W	1
British Thermal Unit/hour	BTU/hour	BTU/hr	unit_BTU_hr	3.415179027
British Thermal Unit/minute	BTU/minute	BTU/min	unit_BTU_min	0.05691965
British Thermal Unit/second	BTU/second	BTU/sec	unit_BTU_sec	0.000948661
Calories/second	Calorie/second	cal/sec	unit_cal_sec	0.239058511
Horsepower	Horse power	hp	unit_hp	0.001341022
Pound-feet/minute	Pound-foot/minute	lb.ft/min	unit_lb_ft_min	44.25372896
Pound-feet/second	Pound-foot/second	lb ft/sec	unit_lb_ft_sec	0.737562149
Mass
Grams	Gram	g	unit_g	1
Carats	Carat	ct	unit_ct	5
Grains	Grain	gr	unit_gr	15.43235835
Ounces	Ounce	oz	unit_oz	0.035273962
Ounces (Troy)	Troy Ounce	oz t	unit_oz_t	0.032150748
Pennyweights	Pennyweight	dwt	unit_dwt	0.643014931
Pounds	Pound	lb	unit_lb	0.002204623
Pounds (Troy)	Troy Pound	lb t	unit_lb_t	0.002679229
Stones	Stone	St	unit_St	0.000157473
Tons (metric)	metric Tonne	T (metric)	unit_T_met	1.00E-06
Tons (imperial)	english Tonnes	T (imperial)	unit_T_imp	1.10E-06
Light
Lux	Lux	lx	unit_lx	1
Flames	Flame	fl	unit_fl	0.02322576
Footcandles	Feetcandles	fc	unit_fc	0.09290304
Meter-candles	Metre-candles	mc	unit_mc	1
Force
Newtons	Newton	N	unit_N	1
Gram Force	Grams Force	gf	unit_gf	101.9716213
Joules/Centimeter	Joules/Centimetre	J/cm	unit_J_cm	100
Joules/Meter	Joules/Metre	J/m	unit_J_m	1
Ounce Force	Ounces Force	ozf	unit_ozf	3.59694309
Pound Force	Pounds Force	lbf	unit_lbf	0.224808943
Temperature
Celsius	deg C	C	unit_C	1
Fahrenheit	deg F	F	unit_F	1.8
Kelvin	deg K	K	unit_K	1
Time
Seconds	Second	sec	unit_sec	1
Centuries	Century	century	unit_century	3.17E-10
Days	Day	da	unit_da	1.16E-05
Decades	Decade	decade	unit_decade	3.17E-09
Fortnights	Fortnight	fortnight	unit_fortnight	8.27E-07
Hours	Hour	hr	unit_hr	0.000277778
Leap-years	Leap-year	leap yr	unit_leap_yr	3.16E-08
Millenniums	Millennium	millennium	unit_millennium	3.17E-11
Minutes	Minute	min	unit_min	0.016666667
Months (30 days)	Month (30 days)	mon	unit_mon	3.86E-07
Weeks	Week	wk	unit_wk	1.65E-06
Years	Year	yr	unit_yr	3.17E-08
Volume
Litres	Liters	l	unit_l	1
Inches3	Inch3	cu in	unit_in3	61.02374409
Feet3	foot3	cu ft	unit_ft3	0.035314667
Yards3	Yard3	cu yd	unit_yd3	0.001307951
Cups	Cup	c	unit_c	4.226752838
Gallons (US)	Gallon (US)	gal (US)	unit_gal_us	0.264172052
Gallons (UK)	Gallon (UK)	gal (UK)	unit_gal_uk	0.219969152
Meters3	Metre3	cu m	unit_m3	0.001
Ounces (US)	Ounce (US)	fl oz (US)	unit_fl_oz_us	33.8140227
Ounces (UK)	Ounce (UK)	fl oz (UK)	unit_fl_oz_uk	35.19506424
Pints	Pint	pt	unit_pt	2.113376419
Quarts	Quart	qt	unit_qt	1.056688209
Tablespoons	Tablespoon	tbsp	unit_tbsp	67.6280454
Teaspoons	Teaspoon	tsp	unit_tsp	202.8841362
Volume - Dry
Litres (Dry)	Liters	l (Dry)	unit_l_dry	1
Barrels	Barrel	bbl	unit_bbl	0.008648489
Bushels (Dry)	Bushel (Dry)	bu	unit_bu	0.028377592
Pecks	Peck	pk	unit_pk	0.113510368
Pints (Dry)	Pint (Dry)	pt (Dry)	unit_pt_dry	1.81616588
Quarts (Dry)	Quart (Dry)	qt (Dry)	unit_qt_dry	0.90808294