WOLFRAM SYSTEM MODELER
ConstantsLibrary of mathematical constants and constants of nature (e.g., pi, eps, R, sigma) |
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Package Constants (22)
| e |
Value: Modelica.Math.exp(1.0) Type: Real |
|---|---|
| pi |
Value: 2 * Modelica.Math.asin(1.0) Type: Real |
| D2R |
Value: pi / 180 Type: Real (rad/°) Description: Degree to Radian |
| R2D |
Value: 180 / pi Type: Real (°/rad) Description: Radian to Degree |
| gamma |
Value: 0.57721566490153286061 Type: Real Description: See http://en.wikipedia.org/wiki/Euler_constant |
| eps |
Value: ModelicaServices.Machine.eps Type: Real Description: The difference between 1 and the least value greater than 1 that is representable in the given floating point type |
| small |
Value: ModelicaServices.Machine.small Type: Real Description: Minimum normalized positive floating-point number |
| inf |
Value: ModelicaServices.Machine.inf Type: Real Description: Maximum representable finite floating-point number |
| Integer_inf |
Value: ModelicaServices.Machine.Integer_inf Type: Integer Description: Biggest Integer number such that Integer_inf and -Integer_inf are representable on the machine |
| c |
Value: 299792458 Type: Velocity (m/s) Description: Speed of light in vacuum |
| g_n |
Value: 9.80665 Type: Acceleration (m/s²) Description: Standard acceleration of gravity on earth |
| G |
Value: 6.67430e-11 Type: Real (m³/(kg⋅s²)) Description: Newtonian constant of gravitation |
| q |
Value: 1.602176634e-19 Type: ElectricCharge (C) Description: Elementary charge |
| F |
Value: q * N_A Type: FaradayConstant (C/mol) Description: Faraday constant, C/mol |
| h |
Value: 6.62607015e-34 Type: Real (J⋅s) Description: Planck constant |
| k |
Value: 1.380649e-23 Type: Real (J/K) Description: Boltzmann constant |
| R |
Value: k * N_A Type: Real (J/(mol⋅K)) Description: Molar gas constant |
| sigma |
Value: 2 * pi ^ 5 * k ^ 4 / (15 * h ^ 3 * c ^ 2) Type: Real (W/(m²⋅K⁴)) Description: Stefan-Boltzmann constant |
| N_A |
Value: 6.02214076e23 Type: Real (1/mol) Description: Avogadro constant |
| mu_0 |
Value: 1.25663706212e-6 Type: Permeability (V⋅s/(A⋅m)) Description: Magnetic constant |
| epsilon_0 |
Value: 1 / (mu_0 * c * c) Type: Real (F/m) Description: Electric constant |
| T_zero |
Value: -273.15 Type: Temperature_degC (°C) Description: Absolute zero temperature |
Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This package provides often needed constants from mathematics, machine dependent constants and constants from nature. The latter constants (name, value, description) are from the following source (based on the second source):
- Michael Stock, Richard Davis, Estefanía de Mirandés and Martin J T Milton:
- The revision of the SI-the result of three decades of progress in metrology in Metrologia, Volume 56, Number 2. https://iopscience.iop.org/article/10.1088/1681-7575/ab0013/pdf, 2019.
- D B Newell, F Cabiati, J Fischer, K Fujii, S G Karshenboim, H S Margolis , E de Mirandés, P J Mohr, F Nez, K Pachucki, T J Quinn, B N Taylor, M Wang, B M Wood and Z Zhang:
- The CODATA 2017 values of h, e, k, and NA for the revision of the SI in Metrologia, Volume 55, Number 1. https://iopscience.iop.org/article/10.1088/1681-7575/aa950a/pdf, 2017.
BIPM is Bureau International des Poids et Mesures (they publish the SI-standard).
CODATA is the Committee on Data for Science and Technology.
- Main Author:
- Martin Otter
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Systemdynamik und Regelungstechnik (SR)
Münchener Straße 20
D-82234 Weßling
Germany
email: Martin.Otter@dlr.de
Copyright © 1998-2025, Modelica Association and contributors
Wolfram Language
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SystemModel["Modelica.Constants"]
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Revisions
- Dec 4, 2019
by Thomas Beutlich:
Constant G updated according to 2018 CODATA value. - Mar 25, 2019
by Hans Olsson:
Constants updated according to 2017 CODATA values and new SI-standard. - Nov 4, 2015
by Thomas Beutlich:
Constants updated according to 2014 CODATA values. - Nov 8, 2004
by Christian Schweiger:
Constants updated according to 2002 CODATA values. - Dec 9, 1999
by Martin Otter:
Constants updated according to 1998 CODATA values. Using names, values and description text from this source. Included magnetic and electric constant. - Sep 18, 1999
by Martin Otter:
Constants eps, inf, small introduced. - Nov 15, 1997
by Martin Otter:
Realized.