physics

Physical constants and unit conversion (1.27.0). Constants are zero-argument functions returning a float. convert scales or transforms a value between units in the same physical dimension.

import physics;

let speed = physics.c();             /* speed of light in m/s */
let km = physics.convert(100.0, "mi", "km");  /* convert 100 miles to km */

Constants

Name Value Units
c() 299792458 m/s (speed of light)
G() 6.6743e-11 m^3 kg^-1 s^-2 (gravitational constant)
planck() 6.62607015e-34 J*s (Planck constant)
hbar() 1.054571817e-34 J*s (reduced Planck constant)
avogadro() 6.02214076e23 mol^-1 (Avogadro constant)
boltzmann() 1.380649e-23 J/K (Boltzmann constant)
gasConstant() 8.314462618 J mol^-1 K^-1 (ideal gas constant)
elementaryCharge() 1.602176634e-19 C (elementary charge)
electronMass() 9.1093837015e-31 kg
protonMass() 1.67262192369e-27 kg
stefanBoltzmann() 5.670374419e-8 W m^-2 K^-4 (Stefan-Boltzmann constant)
gravity() 9.80665 m/s^2 (standard gravity)

convert

physics.convert(value, fromUnit, toUnit)

Converts value from fromUnit to toUnit. Both units must belong to the same physical dimension.

Length

Units: "m", "km", "cm", "mm", "mi", "yd", "ft", "in", "nmi"

physics.convert(1.0, "mi", "km");     /* 1.609344 */
physics.convert(100.0, "cm", "m");    /* 1.0 */

Mass

Units: "kg", "g", "mg", "lb", "oz", "t"

physics.convert(1.0, "lb", "kg");     /* 0.45359237 */

Time

Units: "s", "ms", "us", "ns", "min", "h", "day"

physics.convert(1.0, "h", "s");       /* 3600.0 */

Temperature

Units: "C", "F", "K" (affine conversion; not a simple scaling)

physics.convert(100.0, "C", "F");     /* 212.0 */
physics.convert(0.0, "C", "K");       /* 273.15 */
physics.convert(32.0, "F", "C");      /* 0.0 */

Error handling

  • An unknown unit string raises RuntimeError with the message physics.convert: unknown unit "...".
  • Mixing units from different dimensions (e.g. "km" and "kg") raises RuntimeError with the message physics.convert: dimension mismatch (km is length, kg is mass).
  • Mixing temperature units with scale units raises RuntimeError.
try {
    physics.convert(1.0, "km", "kg");
} catch (RuntimeError e) {
    io.println(e.message); /* physics.convert: dimension mismatch ... */
}
← statscomplex →