manual:chapter3:units

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manual:chapter3:units [2018/10/25 09:34]
claudio 		manual:chapter3:units [2019/09/14 07:03]
jojo1973 Fixed some typos and capitalization
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 Results of an addition or subtraction between consistent units will produce a result with the units of the first argument (argument in level 2 of the stack at the time of the operation, or the left argument in an algebraic expression). Results of an addition or subtraction between consistent units will produce a result with the units of the first argument (argument in level 2 of the stack at the time of the operation, or the left argument in an algebraic expression).
 +
 +Unit conversions can be performed directly using the ''CONVERT'' command, which is accessible directly from the keyboard (**LS-6**). For example to convert 100 ml into m^3 simply place the original unit and the new unit on the stack: ''100_ml'' ''1_m^3'' ''CONVERT''.
 +
 +To reduce a unit to its base components, use the command ''UBASE''. For example ''1_N'' ''UBASE'' will return ''1_kg*m/s^2''.
 +
 +To extract the value part of a unit object, use the ''UVAL'' command, which will return the object without its unit.
 +==== Custom Units ====
 +
 +Units in newRPL can be arbitrary symbols, not just the ones predefined in the system. For example, adding ''3_apples'' and ''2_apples'' will produce ''5_apples'' as expected. In this case, ''apples'' is a custom unit without a definition. Units without a definition are considered base units. The system already includes base units for mass, length, time, etc. but any number of new base units can be added simply by using new symbols.
 +
 +Custom units can also be defined as derived units, in terms of other base units. This is done with the ''UDEFINE'' command. For example typing ''750_ml'' ''%%'bigmug'%%'' ''UDEFINE'' would define a unit named ''bigmug'' as 750 ml. From that moment ''bigmug'' can be used in the exact same way as any system-defined unit, and it will be considered consistent with all other volume units.
 +
 +New units can also be defined in terms of new (unknown) base units. For example typing ''3_apples'' ''%%'oranges'%%'' ''UDEFINE'' will define ''oranges'' as equivalent to 3 ''apples'', where ''apples'' is a base unit (amount of fruit?).
 +From that moment the addition ''2_[oranges]+3_[apples]'' will result in ''3_oranges'' since the units of the result will match the units of the left operand, and the 3 apples were automatically converted to 1 orange.
 +
 +Custom units work systemwide, the command ''ULIST'' returns a list of all the custom units that are defined in the system. To remove a unit definition use the ''UPURGE'' command. Following the previous example, typing ''%%'oranges'%%'' ''UPURGE'' will undefine the unit. Notice that the unit ''oranges'' definition was removed, which means this symbol now represents an unknown base unit, then ''2_[oranges]+3_[apples]'' cannot proceed since oranges and apples are now considered as unrelated base units.
 +
 +
 +==== Available Units ====
  
 This is a list of the units available in the ''Units'' menu on newRPL: This is a list of the units available in the ''Units'' menu on newRPL:
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 | 1_ftUS | surveying foot | 1_ftUS = 1200/3937_m | US surveying length |  | 1_ftUS | surveying foot | 1_ftUS = 1200/3937_m | US surveying length | 
 | 1_mil | thousandth of inch | 1_mil = 0.001_in | US customary length |  | 1_mil | thousandth of inch | 1_mil = 0.001_in | US customary length | 
-| 1_µ | micron or micrometre | 1_µ = 1_µm | SI length |  +| 1_µ | micron | 1_µ = 1_µm | SI length |  
-| 1_Å | Ångström | 1_Å = 0.1_nm | non-SI length |  +| 1_Å | ångström | 1_Å = 0.1_nm | non-SI length |  
-| 1_fermi | fermi or femtometre | 1_fermi = 1_fm | SI length | +| 1_fermi | fermi  | 1_fermi = 1_fm | SI length | 
  
 | **Area** |||| | **Area** ||||
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 | 1_cu | cup | 1_cu = 1/16_gal | US customary volume |  | 1_cu | cup | 1_cu = 1/16_gal | US customary volume | 
 | 1_ozfl | fluid ounce | 1_ozfl = 1/128_gal | US customary volume |  | 1_ozfl | fluid ounce | 1_ozfl = 1/128_gal | US customary volume | 
-| 1_tbsp | table spoon | 1_tbsp = 1/2_ozfl | US customary volume |  +| 1_tbsp | tablespoon | 1_tbsp = 1/2_ozfl | US customary volume |  
-| 1_tsp | tea spoon | 1_tsp = 1/6_ozfl | US customary volume | +| 1_tsp | teaspoon | 1_tsp = 1/6_ozfl | US customary volume | 
 | 1_fbm | board foot | 1_fbm = 144_in%%^%%3 | US customary volume |  | 1_fbm | board foot | 1_fbm = 144_in%%^%%3 | US customary volume | 
 | 1_galUK | gallon (UK) | 1_galUK = 0.00454609_m%%^%%3 | Imperial volume |  | 1_galUK | gallon (UK) | 1_galUK = 0.00454609_m%%^%%3 | Imperial volume | 
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 | **Time** |||| | **Time** ||||
 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
-| 1_yr | tropical year | 1_yr = 31556925.9747_sper  | 1952 Ephemeris Time | +| 1_yr | tropical year | 1_yr = 31556925.9747_s  |  per 1952 Ephemeris Time | 
 | 1_d | day | 1_d = 86400_s | SI time | | 1_d | day | 1_d = 86400_s | SI time |
 | 1_h | hour | 1_h = 3600_s | SI time |  | 1_h | hour | 1_h = 3600_s | SI time | 
 | 1_min | minute | 1_min = 60_s | SI time |  | 1_min | minute | 1_min = 60_s | SI time | 
 | 1_s | second | 1_s | Base SI unit of time |  | 1_s | second | 1_s | Base SI unit of time | 
-| 1_Hz | Hertz | 1_Hz = 1_1/s | SI frequency |+| 1_Hz | hertz | 1_Hz = 1_1/s | SI frequency |
  
 | **Speed** |||| | **Speed** ||||
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 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
 | 1_kg | kilogram | 1_kg | Base SI unit of mass |  | 1_kg | kilogram | 1_kg | Base SI unit of mass | 
-| 1_g | kilogram | 1_g = 0.001_kg | SI mass | +| 1_g | gram | 1_g = 0.001_kg | SI mass | 
 | 1_lb | pound | 1_lb = 7000_grain | US customary mass |  | 1_lb | pound | 1_lb = 7000_grain | US customary mass | 
 | 1_oz | ounce | 1_oz = 1/16_lb | US customary mass |  | 1_oz | ounce | 1_oz = 1/16_lb | US customary mass | 
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 | 1_ton | tonne | 1_ton = 2000_lb | US customary mass |  | 1_ton | tonne | 1_ton = 2000_lb | US customary mass | 
 | 1_tonUK | tonne (UK) | 1_tonUK = 2240_lb | Imperial mass |  | 1_tonUK | tonne (UK) | 1_tonUK = 2240_lb | Imperial mass | 
-| 1_t | Metric tonne | 1_t = 1000_kg | non-SI mass | +| 1_t | metric tonne | 1_t = 1000_kg | non-SI mass | 
 | 1_ozt | troy ounce | 1_ozt = 480_grain | Imperial mass |  | 1_ozt | troy ounce | 1_ozt = 480_grain | Imperial mass | 
-| 1_ct | Metric carat | 1_ct = 200_mg | Metric System mass | +| 1_ct | metric carat | 1_ct = 200_mg | Metric System mass | 
 | 1_grain | grain | 1_grain = 64.79891_mg | Imperial mass |  | 1_grain | grain | 1_grain = 64.79891_mg | Imperial mass | 
 | 1_u | unified atomic mass | 1_u = 1.660539040E-27_kg | non-SI mass |  | 1_u | unified atomic mass | 1_u = 1.660539040E-27_kg | non-SI mass | 
 | 1_mol | mole | 1_mol | Base SI amount of substance |  | 1_mol | mole | 1_mol | Base SI amount of substance | 
 | 1_gmol | gram mole | 1_gmol = 1_mol | non-SI amount of substance | | 1_gmol | gram mole | 1_gmol = 1_mol | non-SI amount of substance |
-| 1_lbmol | pound mole | 1_lbmol = 453.59237_mol | US customary substance |+| 1_lbmol | pound mole | 1_lbmol = 453.59237_mol | US customary amount of substance |
  
 | **Force** |||| | **Force** ||||
 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
-| 1_N | Newton | 1_N = 1_kg*m/s%%^%%2 | SI force | +| 1_N | newton | 1_N = 1_kg*m/s%%^%%2 | SI force | 
 | 1_dyn | dyne | 1_dyn = 1_g*cm/s%%^%%2 | non-SI force |  | 1_dyn | dyne | 1_dyn = 1_g*cm/s%%^%%2 | non-SI force | 
 | 1_gf | gram-force | 1_gf = 1_g*ga | non-SI force |  | 1_gf | gram-force | 1_gf = 1_g*ga | non-SI force | 
 | 1_kip | kip | 1_kip = 1000_lbf | US customary force |  | 1_kip | kip | 1_kip = 1000_lbf | US customary force | 
 | 1_lbf | pound-force | 1_lbf = 1_lb*ga | US customary force |  | 1_lbf | pound-force | 1_lbf = 1_lb*ga | US customary force | 
-| 1_pdl | poundal | 1_pdl = = 1_lb*ft/s%%^%%2 | US customary force | +| 1_pdl | poundal | 1_pdl = 1_lb*ft/s%%^%%2 | US customary force | 
  
 | **Energy** |||| | **Energy** ||||
 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
-| 1_J | Joule | 1_J = 1_N*m | SI energy | +| 1_J | joule | 1_J = 1_N*m | SI energy | 
 | 1_kW*h | kilowatt-hour | 1_kW*h = 3.6_MJ | non-SI energy |  | 1_kW*h | kilowatt-hour | 1_kW*h = 3.6_MJ | non-SI energy | 
 | 1_erg | erg | 1_erg = 1_dyn*cm | non-SI energy |  | 1_erg | erg | 1_erg = 1_dyn*cm | non-SI energy | 
-| 1_kcal | kilo calorie | 1_kcal = 1000_cal | non-SI energy |  +| 1_kcal | kilocalorie (thermochemical) | 1_kcal = 1000_cal | non-SI energy |  
-| 1_cal | calorie | 1_cal = 4.184_J | non-SI energy | +| 1_cal | calorie (thermochemical) | 1_cal = 4.184_J | non-SI energy | 
 | 1_Btu | british thermal unit | 1_Btu = =1055.056_J | Imperial energy |  | 1_Btu | british thermal unit | 1_Btu = =1055.056_J | Imperial energy | 
 | 1_ft*lbf | foot-pound | 1_ft*lbf = 1_lb*ft*ga | US customary energy |  | 1_ft*lbf | foot-pound | 1_ft*lbf = 1_lb*ft*ga | US customary energy | 
 | 1_therm | therm | 1_therm = 100000_Btu | Imperial energy |  | 1_therm | therm | 1_therm = 100000_Btu | Imperial energy | 
-| 1_MeV | mega electronvolt | 1_MeV = 1E6_eV | non-SI energy | +| 1_MeV | megaelectronvolt | 1_MeV = 1E6_eV | non-SI energy | 
 | 1_eV | electronvolt | 1_eV = 1.6021766208E-19_J | non-SI energy | | 1_eV | electronvolt | 1_eV = 1.6021766208E-19_J | non-SI energy |
  
 | **Power** |||| | **Power** ||||
 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
-| 1_W | Watt | 1_W = 1_J/s | SI power |+| 1_W | watt | 1_W = 1_J/s | SI power |
 | 1_kW | kilowatt | 1_kW = 1000_W | SI power | | 1_kW | kilowatt | 1_kW = 1000_W | SI power |
 | 1_MW | megawatt | 1_MW = 1000000_W | SI power |  | 1_MW | megawatt | 1_MW = 1000000_W | SI power | 
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 | **Pressure** |||| | **Pressure** ||||
 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
-| 1_Pa | Pascal | 1_Pa = 1_N/m%%^%%2 | SI pressure | +| 1_Pa | pascal | 1_Pa = 1_N/m%%^%%2 | SI pressure | 
 | 1_atm | atmospheric pressure | 1_atm = 101325_Pa | non-SI pressure |  | 1_atm | atmospheric pressure | 1_atm = 101325_Pa | non-SI pressure | 
 | 1_bar | bar | 1_bar = 100000_Pa | non-SI pressure |  | 1_bar | bar | 1_bar = 100000_Pa | non-SI pressure | 
 | 1_psi | pound per square inch | 1_psi = 1_lbf/in%%^%%2 | US customary pressure |  | 1_psi | pound per square inch | 1_psi = 1_lbf/in%%^%%2 | US customary pressure | 
-| 1_Torr | Torricelli | 1_Torr = 1/760_atm | non-SI pressure | +| 1_Torr | torr | 1_Torr = 1/760_atm | non-SI pressure | 
 | 1_mmHg | millimetres of mercury (at 0°C) | 1_mmHg = 13595.1_kg/m%%^%%3*mm*ga | non-SI pressure |  | 1_mmHg | millimetres of mercury (at 0°C) | 1_mmHg = 13595.1_kg/m%%^%%3*mm*ga | non-SI pressure | 
 | 1_inHg | inches of mercury (at 0°C) | 1_inHg = 13595.1_kg/m%%^%%3*in*ga | non-SI pressure |  | 1_inHg | inches of mercury (at 0°C) | 1_inHg = 13595.1_kg/m%%^%%3*in*ga | non-SI pressure | 
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 | **Temperature** |||| | **Temperature** ||||
 | Unit | Unit name | Definition | Description | | Unit | Unit name | Definition | Description |
-| 1_°C | celsius (or degree celsius) | 1_°C Zero: 0_°C → 273.15_K | Base SI temperature (rel. scale) | +| 1_°C | celsius (or degree Celsius) | 1_°C Zero: 0_°C → 273.15_K | Base SI temperature (rel. scale) | 
 | 1_Δ°C | celsius temperature change | 1_Δ°C = 1_ΔK | Change of temperature | | 1_Δ°C | celsius temperature change | 1_Δ°C = 1_ΔK | Change of temperature |
-| 1_°F | farenheit (or degree farenheit) | 1_°F Zero: 0_°F → 459.67_°R | US cust. temp. (rel. scale) | +| 1_°F | farenheit (or degree Farenheit) | 1_°F Zero: 0_°F → 459.67_°R | US cust. temp. (rel. scale) | 
 | 1_Δ°F | farenheit temperature change | 1_Δ°F = 1_Δ°R | Change of temperature |  | 1_Δ°F | farenheit temperature change | 1_Δ°F = 1_Δ°R | Change of temperature | 
 | 1_K | kelvin | 1_K | Base SI temperature (abs. scale) |  | 1_K | kelvin | 1_K | Base SI temperature (abs. scale) | 
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 | 1_Fdy | faraday | 1_Fdy = 96485.33289_C | non-SI electrical charge |  | 1_Fdy | faraday | 1_Fdy = 96485.33289_C | non-SI electrical charge | 
 | 1_H | henry | 1_H = 1_Wb/A | SI inductance |  | 1_H | henry | 1_H = 1_Wb/A | SI inductance | 
-| 1_mho | mho (Siemens) | 1_mho = 1_S | non-SI conductance | +| 1_mho | mho | 1_mho = 1_S | non-SI conductance | 
 | 1_S | siemens | 1_S = 1_1/Ω | SI conductance |  | 1_S | siemens | 1_S = 1_1/Ω | SI conductance | 
 | 1_T | tesla | 1_T = 1_Wb/m%%^%%2 | SI magnetic flux density |  | 1_T | tesla | 1_T = 1_Wb/m%%^%%2 | SI magnetic flux density | 
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 | 1_Bq | becquerel | 1_Bq = 1_1/s | SI radiation |  | 1_Bq | becquerel | 1_Bq = 1_1/s | SI radiation | 
 | 1_Ci | curie | 1_Ci = 3.7E10_Bq | non-SI radiation |  | 1_Ci | curie | 1_Ci = 3.7E10_Bq | non-SI radiation | 
-| 1_R | rontgen | 1_R = 2.58E-4_C/kg | non-SI radiation |+| 1_R | roentgen | 1_R = 2.58E-4_C/kg | non-SI radiation |
  
 | **Viscosity** |||| | **Viscosity** ||||
  • manual/chapter3/units.txt
  • Last modified: 2019/11/19 13:34
  • by claudio