# pygments-main / tests / examplefiles / Constants.mo

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158``` ```within Modelica; package Constants "Library of mathematical constants and constants of nature (e.g., pi, eps, R, sigma)" import SI = Modelica.SIunits; import NonSI = Modelica.SIunits.Conversions.NonSIunits; extends Modelica.Icons.Library2; // Mathematical constants final constant Real e=Modelica.Math.exp(1.0); final constant Real pi=2*Modelica.Math.asin(1.0); // 3.14159265358979; final constant Real D2R=pi/180 "Degree to Radian"; final constant Real R2D=180/pi "Radian to Degree"; // Machine dependent constants // (the definition is a temporary fix since not adapted to the // machine where the Modelica translator is running) final constant Real eps=1.e-15 "Biggest number such that 1.0 + eps = 1.0"; final constant Real small=1.e-60 "Smallest number such that small and -small are representable on the machine"; final constant Real inf=1.e+60 "Biggest Real number such that inf and -inf are representable on the machine"; final constant Integer Integer_inf=2147483647 "Biggest Integer number such that Integer_inf and -Integer_inf are representable on the machine"; // Constants of nature // (name, value, description from http://physics.nist.gov/cuu/Constants/) final constant SI.Velocity c=299792458 "Speed of light in vacuum"; final constant SI.Acceleration g_n=9.80665 "Standard acceleration of gravity on earth"; final constant Real G(final unit="m3/(kg.s2)") = 6.6742e-11 "Newtonian constant of gravitation"; final constant SI.FaradayConstant F = 9.64853399e4 "Faraday constant, C/mol"; final constant Real h(final unit="J.s") = 6.6260693e-34 "Planck constant"; final constant Real k(final unit="J/K") = 1.3806505e-23 "Boltzmann constant"; final constant Real R(final unit="J/(mol.K)") = 8.314472 "Molar gas constant"; final constant Real sigma(final unit="W/(m2.K4)") = 5.670400e-8 "Stefan-Boltzmann constant"; final constant Real N_A(final unit="1/mol") = 6.0221415e23 "Avogadro constant"; final constant Real mue_0(final unit="N/A2") = 4*pi*1.e-7 "Magnetic constant"; final constant Real epsilon_0(final unit="F/m") = 1/(mue_0*c*c) "Electric constant"; final constant NonSI.Temperature_degC T_zero=-273.15 "Absolute zero temperature"; annotation ( Documentation(info="

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:

Peter J. Mohr and Barry N. Taylor (1999):
CODATA Recommended Values of the Fundamental Physical Constants: 1998. Journal of Physical and Chemical Reference Data, Vol. 28, No. 6, 1999 and Reviews of Modern Physics, Vol. 72, No. 2, 2000. See also http://physics.nist.gov/cuu/Constants/

CODATA is the Committee on Data for Science and Technology.

Main Author:
Martin Otter
Deutsches Zentrum für Luft und Raumfahrt e. V. (DLR)
Oberpfaffenhofen
Postfach 11 16
D-82230 Weßling
email: Martin.Otter@dlr.de

Copyright © 1998-2009, Modelica Association and DLR.

This Modelica package is free software; it can be redistributed and/or modified under the terms of the Modelica license, see the license conditions and the accompanying disclaimer here.

", revisions="
• 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.
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