1.前言

　　在前几篇关于Math.NET的博客中(见上面链接)，主要是介绍了Math.NET中主要的数值功能，并进行了简单的矩阵向量计算例子，接着使用Math.NET的矩阵等对象，对3种常用的矩阵数据交换格式的读写。一方面可以了解Math.NET的使用，另一方面以后也可以直接读取和保存数据为这两种格式，并在第六篇中介绍了直接求解线性方程组的方法，下面介绍一个Math.NET中非常有用的类：Constants，其中封装了大量的数学及物理常数，可以直接拿来使用。

　　如果本文资源或者显示有问题，请参考：

　　Math.NET中的数学物理常数类包括5个类型,下面分别一一进行介绍，主要是对源码的参数进行翻译，更加直观，使用的话根据自己的需要，就无需多说。

2.数学常数

　　数学常数都是Double类型，已经非常精确了。直接看源码注释即可，部分没有翻译的，很少用到，看英文吧。　　

1 /// 数学常数 e ,也称 欧拉数（Euler's number）
  2 public const double E = 2.7182818284590452353602874713526624977572470937000d;  3   4 /// log[2](e)：2为底,e的对数
  5 public const double Log2E = 1.4426950408889634073599246810018921374266459541530d;  6   7 /// log[10](e)：10为底，e的对数
  8 public const double Log10E = 0.43429448190325182765112891891660508229439700580366d;  9  10 /// log[e](2)：e为底，2的对数
 11 public const double Ln2 = 0.69314718055994530941723212145817656807550013436026d; 12  13 /// log[e](10)：e为底，10的对数
 14 public const double Ln10 = 2.3025850929940456840179914546843642076011014886288d; 15  16 /// log[e](pi)：e为底,pi的对数
 17 public const double LnPi = 1.1447298858494001741434273513530587116472948129153d; 18  19 /// log[e](2*pi)/2
 20 public const double Ln2PiOver2 = 0.91893853320467274178032973640561763986139747363780d; 21  22 /// 1/e：e的倒数
 23 public const double InvE = 0.36787944117144232159552377016146086744581113103176d; 24  25 /// sqrt(e)
 26 public const double SqrtE = 1.6487212707001281468486507878141635716537761007101d; 27  28 /// sqrt(2)
 29 public const double Sqrt2 = 1.4142135623730950488016887242096980785696718753769d; 30  31 /// sqrt(3)
 32 public const double Sqrt3 = 1.7320508075688772935274463415058723669428052538104d; 33  34 /// sqrt(1/2) = 1/sqrt(2) = sqrt(2)/2
 35 public const double Sqrt1Over2 = 0.70710678118654752440084436210484903928483593768845d; 36  37 /// sqrt(3)/2
 38 public const double HalfSqrt3 = 0.86602540378443864676372317075293618347140262690520d; 39  40 /// pi，圆周率
 41 public const double Pi = 3.1415926535897932384626433832795028841971693993751d; 42  43 /// pi*2
 44 public const double Pi2 = 6.2831853071795864769252867665590057683943387987502d; 45  46 /// pi/2
 47 public const double PiOver2 = 1.5707963267948966192313216916397514420985846996876d; 48  49 /// pi*3/2
 50 public const double Pi3Over2 = 4.71238898038468985769396507491925432629575409906266d; 51  52 /// pi/4
 53 public const double PiOver4 = 0.78539816339744830961566084581987572104929234984378d; 54  55 /// sqrt(pi)
 56 public const double SqrtPi = 1.7724538509055160272981674833411451827975494561224d; 57  58 /// sqrt(2pi)
 59 public const double Sqrt2Pi = 2.5066282746310005024157652848110452530069867406099d; 60  61 /// sqrt(2*pi*e)
 62 public const double Sqrt2PiE = 4.1327313541224929384693918842998526494455219169913d; 63  64 /// log(sqrt(2*pi))
 65 public const double LogSqrt2Pi = 0.91893853320467274178032973640561763986139747363778; 66  67 /// log(sqrt(2*pi*e))
 68 public const double LogSqrt2PiE = 1.4189385332046727417803297364056176398613974736378d; 69  70 /// log(2 * sqrt(e / pi))
 71 public const double LogTwoSqrtEOverPi = 0.6207822376352452223455184457816472122518527279025978; 72  73 /// 1/pi
 74 public const double InvPi = 0.31830988618379067153776752674502872406891929148091d; 75  76 /// 2/pi
 77 public const double TwoInvPi = 0.63661977236758134307553505349005744813783858296182d; 78  79 /// 1/sqrt(pi)
 80 public const double InvSqrtPi = 0.56418958354775628694807945156077258584405062932899d; 81  82 /// 1/sqrt(2pi)
 83 public const double InvSqrt2Pi = 0.39894228040143267793994605993438186847585863116492d; 84  85 /// 2/sqrt(pi)
 86 public const double TwoInvSqrtPi = 1.1283791670955125738961589031215451716881012586580d; 87  88 /// 2 * sqrt(e / pi)
 89 public const double TwoSqrtEOverPi = 1.8603827342052657173362492472666631120594218414085755; 90  91 /// (pi)/180 - 角度与弧度的转换常数
 92 /// 
       93 /// 
       94 public const double Degree = 0.017453292519943295769236907684886127134428718885417d; 95  96 ///  (pi)/200 - factor to convert from NewGrad (grad) to Radians (rad).
 97 /// 
       98 /// 
       99 public const double Grad = 0.015707963267948966192313216916397514420985846996876d;100 101 /// The number ln(10)/20 - factor to convert from Power Decibel (dB) to Neper (Np). Use this version when the Decibel represent a power gain but the compared values are not powers (e.g. amplitude, current, voltage).
102 public const double PowerDecibel = 0.11512925464970228420089957273421821038005507443144d;103 104 /// The number ln(10)/10 - factor to convert from Neutral Decibel (dB) to Neper (Np). Use this version when either both or neither of the Decibel and the compared values represent powers.
105 public const double NeutralDecibel = 0.23025850929940456840179914546843642076011014886288d;106 107 /// The Catalan constant
108 /// 
      
       Sum(k=0 -> inf){ (-1)^k/(2*k + 1)2 }
      109 public const double Catalan = 0.9159655941772190150546035149323841107741493742816721342664981196217630197762547694794d;110 111 /// The Euler-Mascheroni constant
112 /// 
      
       lim(n -> inf){ Sum(k=1 -> n) { 1/k - log(n) } }
      113 public const double EulerMascheroni = 0.5772156649015328606065120900824024310421593359399235988057672348849d;114 115 /// (1+sqrt(5))/2, 黄金比例
116 public const double GoldenRatio = 1.6180339887498948482045868343656381177203091798057628621354486227052604628189024497072d;117 118 /// Glaisher常数
119 /// 
      
       e^(1/12 - Zeta(-1))
      120 public const double Glaisher = 1.2824271291006226368753425688697917277676889273250011920637400217404063088588264611297d;121 122 /// Khinchin常数
123 /// 
      
       prod(k=1 -> inf){1+1/(k*(k+2))^log(k,2)}
      124 public const double Khinchin = 2.6854520010653064453097148354817956938203822939944629530511523455572188595371520028011d;

3.普适常数　　

1 /// 真空中的光速: c_0 = 2.99792458e8 [m s^-1] (defined, exact; 2007 CODATA)
 2 public const double SpeedOfLight = 2.99792458e8; 3  4 /// 真空中的磁导率: mu_0 = 4*Pi * 10^-7 [N A^-2 = kg m A^-2 s^-2] (defined, exact; 2007 CODATA)
 5 public const double MagneticPermeability = 1.2566370614359172953850573533118011536788677597500e-6; 6  7 /// 真空中的介电常数: epsilon_0 = 1/(mu_0*c_0^2) [F m^-1 = A^2 s^4 kg^-1 m^-3] (defined, exact; 2007 CODATA)
 8 public const double ElectricPermittivity = 8.8541878171937079244693661186959426889222899381429e-12; 9 10 /// 真空中的特性阻抗常数: Z_0 = mu_0*c_0 [Ohm = m^2 kg s^-3 A^-2] (defined, exact; 2007 CODATA)
11 public const double CharacteristicImpedanceVacuum = 376.73031346177065546819840042031930826862350835242;12 13 /// 牛顿引力常数: G = 6.67429e-11 [m^3 kg^-1 s^-2] (2007 CODATA)
14 public const double GravitationalConstant = 6.67429e-11;15 16 /// 普朗克常数: h = 6.62606896e-34 [J s = m^2 kg s^-1] (2007 CODATA)
17 public const double PlancksConstant = 6.62606896e-34;18 19 /// 约化普朗克常数: h_bar = h / (2*Pi) [J s = m^2 kg s^-1] (2007 CODATA)
20 public const double DiracsConstant = 1.054571629e-34;21 22 /// 普朗克质量: m_p = (h_bar*c_0/G)^(1/2) [kg] (2007 CODATA)
23 public const double PlancksMass = 2.17644e-8;24 25 /// 普朗克温度: T_p = (h_bar*c_0^5/G)^(1/2)/k [K] (2007 CODATA)
26 public const double PlancksTemperature = 1.416786e32;27 28 /// 普朗克长度: l_p = h_bar/(m_p*c_0) [m] (2007 CODATA)
29 public const double PlancksLength = 1.616253e-35;30 31 /// 普朗克时间: t_p = l_p/c_0 [s] (2007 CODATA)
32 public const double PlancksTime = 5.39124e-44;

4.电磁常数　　

1 /// 基本电子电荷: e = 1.602176487e-19 [C = A s] (2007 CODATA)
 2 public const double ElementaryCharge = 1.602176487e-19; 3  4 /// 磁通量子: theta_0 = h/(2*e) [Wb = m^2 kg s^-2 A^-1] (2007 CODATA)
 5 public const double MagneticFluxQuantum = 2.067833668e-15; 6  7 /// 电导量子(Conductance Quantum): G_0 = 2*e^2/h [S = m^-2 kg^-1 s^3 A^2] (2007 CODATA)
 8 public const double ConductanceQuantum = 7.7480917005e-5; 9 10 /// 约瑟夫森效应常数(Josephson Constant): K_J = 2*e/h [Hz V^-1] (2007 CODATA)
11 public const double JosephsonConstant = 483597.891e9;12 13 /// 克里青常数(Von Klitzing Constant): R_K = h/e^2 [Ohm = m^2 kg s^-3 A^-2] (2007 CODATA)
14 public const double VonKlitzingConstant = 25812.807557;15 16 /// 玻尔磁子(Bohr Magneton): mu_B = e*h_bar/2*m_e [J T^-1] (2007 CODATA)
17 public const double BohrMagneton = 927.400915e-26;18 19 /// 核磁子(Nuclear Magneton): mu_N = e*h_bar/2*m_p [J T^-1] (2007 CODATA)
20 public const double NuclearMagneton = 5.05078324e-27;

5.原子和核常量

　　一些常用的：　　

1 /// 精细结构常数(Fine Structure Constant): alpha = e^2/4*Pi*e_0*h_bar*c_0 [1] (2007 CODATA)
 2 public const double FineStructureConstant = 7.2973525376e-3; 3  4 /// 里德伯常量(Rydberg Constant): R_infty = alpha^2*m_e*c_0/2*h [m^-1] (2007 CODATA)
 5 public const double RydbergConstant = 10973731.568528; 6  7 /// Bor Radius: a_0 = alpha/4*Pi*R_infty [m] (2007 CODATA)
 8 public const double BohrRadius = 0.52917720859e-10; 9 10 /// Hartree Energy: E_h = 2*R_infty*h*c_0 [J] (2007 CODATA)
11 public const double HartreeEnergy = 4.35974394e-18;12 13 /// Quantum of Circulation: h/2*m_e [m^2 s^-1] (2007 CODATA)
14 public const double QuantumOfCirculation = 3.6369475199e-4;15 16 /// Fermi Coupling Constant: G_F/(h_bar*c_0)^3 [GeV^-2] (2007 CODATA)
17 public const double FermiCouplingConstant = 1.16637e-5;18 19 /// Weak Mixin Angle: sin^2(theta_W) [1] (2007 CODATA)
20 public const double WeakMixingAngle = 0.22256;21 22 /// 电子质量(Electron Mass): [kg] (2007 CODATA)
23 public const double ElectronMass = 9.10938215e-31;24 25 /// Electron Mass Energy Equivalent: [J] (2007 CODATA)
26 public const double ElectronMassEnergyEquivalent = 8.18710438e-14;27 28 /// 电子摩尔质量(Electron Molar Mass): [kg mol^-1] (2007 CODATA)
29 public const double ElectronMolarMass = 5.4857990943e-7;30 31 /// 电子的康普顿波长(Electron Compton Wavelength): [m] (2007 CODATA)
32 public const double ComptonWavelength = 2.4263102175e-12;33 34 /// 经典电子半径(Classical Electron Radius): [m] (2007 CODATA)
35 public const double ClassicalElectronRadius = 2.8179402894e-15;36 37 /// Tomson Cross Section: [m^2] (2002 CODATA)
38 public const double ThomsonCrossSection = 0.6652458558e-28;39 40 /// 电子磁矩(Electron Magnetic Moment): [J T^-1] (2007 CODATA)
41 public const double ElectronMagneticMoment = -928.476377e-26;

还有一些不常用的，需要在很专业的地方才能用得上，代码折叠了：　　

1 /// Electon G-Factor: [1] (2007 CODATA)
  2 public const double ElectronGFactor = -2.0023193043622;  3   4 /// μ介子质量(Muon Mass): [kg] (2007 CODATA)
  5 public const double MuonMass = 1.88353130e-28;  6   7 /// Muon Mass Energy Equivalent: [J] (2007 CODATA)
  8 public const double MuonMassEnegryEquivalent = 1.692833511e-11;  9  10 /// Muon Molar Mass: [kg mol^-1] (2007 CODATA)
 11 public const double MuonMolarMass = 0.1134289256e-3; 12  13 /// Muon Compton Wavelength: [m] (2007 CODATA)
 14 public const double MuonComptonWavelength = 11.73444104e-15; 15  16 /// Muon Magnetic Moment: [J T^-1] (2007 CODATA)
 17 public const double MuonMagneticMoment = -4.49044786e-26; 18  19 /// Muon G-Factor: [1] (2007 CODATA)
 20 public const double MuonGFactor = -2.0023318414; 21  22 /// Tau Mass: [kg] (2007 CODATA)
 23 public const double TauMass = 3.16777e-27; 24  25 /// Tau Mass Energy Equivalent: [J] (2007 CODATA)
 26 public const double TauMassEnergyEquivalent = 2.84705e-10; 27  28 /// Tau Molar Mass: [kg mol^-1] (2007 CODATA)
 29 public const double TauMolarMass = 1.90768e-3; 30  31 /// Tau Compton Wavelength: [m] (2007 CODATA)
 32 public const double TauComptonWavelength = 0.69772e-15; 33  34 /// Proton Mass: [kg] (2007 CODATA)
 35 public const double ProtonMass = 1.672621637e-27; 36  37 /// Proton Mass Energy Equivalent: [J] (2007 CODATA)
 38 public const double ProtonMassEnergyEquivalent = 1.503277359e-10; 39  40 /// Proton Molar Mass: [kg mol^-1] (2007 CODATA)
 41 public const double ProtonMolarMass = 1.00727646677e-3; 42  43 /// Proton Compton Wavelength: [m] (2007 CODATA)
 44 public const double ProtonComptonWavelength = 1.3214098446e-15; 45  46 /// Proton Magnetic Moment: [J T^-1] (2007 CODATA)
 47 public const double ProtonMagneticMoment = 1.410606662e-26; 48  49 /// Proton G-Factor: [1] (2007 CODATA)
 50 public const double ProtonGFactor = 5.585694713; 51  52 /// Proton Shielded Magnetic Moment: [J T^-1] (2007 CODATA)
 53 public const double ShieldedProtonMagneticMoment = 1.410570419e-26; 54  55 /// Proton Gyro-Magnetic Ratio: [s^-1 T^-1] (2007 CODATA)
 56 public const double ProtonGyromagneticRatio = 2.675222099e8; 57  58 /// Proton Shielded Gyro-Magnetic Ratio: [s^-1 T^-1] (2007 CODATA)
 59 public const double ShieldedProtonGyromagneticRatio = 2.675153362e8; 60  61 /// 中子质量(Neutron Mass): [kg] (2007 CODATA)
 62 public const double NeutronMass = 1.674927212e-27; 63  64 /// Neutron Mass Energy Equivalent: [J] (2007 CODATA)
 65 public const double NeutronMassEnegryEquivalent = 1.505349506e-10; 66  67 /// Neutron Molar Mass: [kg mol^-1] (2007 CODATA)
 68 public const double NeutronMolarMass = 1.00866491597e-3; 69  70 /// Neuron Compton Wavelength: [m] (2007 CODATA)
 71 public const double NeutronComptonWavelength = 1.3195908951e-1; 72  73 /// Neutron Magnetic Moment: [J T^-1] (2007 CODATA)
 74 public const double NeutronMagneticMoment = -0.96623641e-26; 75  76 /// Neutron G-Factor: [1] (2007 CODATA)
 77 public const double NeutronGFactor = -3.82608545; 78  79 /// Neutron Gyro-Magnetic Ratio: [s^-1 T^-1] (2007 CODATA)
 80 public const double NeutronGyromagneticRatio = 1.83247185e8; 81  82 /// 氘核质量(Deuteron Mass): [kg] (2007 CODATA)
 83 public const double DeuteronMass = 3.34358320e-27; 84  85 /// Deuteron Mass Energy Equivalent: [J] (2007 CODATA)
 86 public const double DeuteronMassEnegryEquivalent = 3.00506272e-10; 87  88 /// Deuteron Molar Mass: [kg mol^-1] (2007 CODATA)
 89 public const double DeuteronMolarMass = 2.013553212725e-3; 90  91 /// Deuteron Magnetic Moment: [J T^-1] (2007 CODATA)
 92 public const double DeuteronMagneticMoment = 0.433073465e-26; 93  94 /// Helion Mass: [kg] (2007 CODATA)
 95 public const double HelionMass = 5.00641192e-27; 96  97 /// Helion Mass Energy Equivalent: [J] (2007 CODATA)
 98 public const double HelionMassEnegryEquivalent = 4.49953864e-10; 99 100 /// Helion Molar Mass: [kg mol^-1] (2007 CODATA)
101 public const double HelionMolarMass = 3.0149322473e-3;102 103 /// Avogadro constant: [mol^-1] (2010 CODATA)
104 public const double Avogadro = 6.0221412927e23;

View Code

6.科学计算前缀

1 /// The SI prefix factor corresponding to 1 000 000 000 000 000 000 000 000
 2 public const double Yotta = 1e24; 3  4 /// The SI prefix factor corresponding to 1 000 000 000 000 000 000 000
 5 public const double Zetta = 1e21; 6  7 /// The SI prefix factor corresponding to 1 000 000 000 000 000 000
 8 public const double Exa = 1e18; 9 10 /// The SI prefix factor corresponding to 1 000 000 000 000 000
11 public const double Peta = 1e15;12 13 /// The SI prefix factor corresponding to 1 000 000 000 000
14 public const double Tera = 1e12;15 16 /// The SI prefix factor corresponding to 1 000 000 000
17 public const double Giga = 1e9;18 19 /// The SI prefix factor corresponding to 1 000 000
20 public const double Mega = 1e6;21 22 /// The SI prefix factor corresponding to 1 000
23 public const double Kilo = 1e3;24 25 /// The SI prefix factor corresponding to 100
26 public const double Hecto = 1e2;27 28 /// The SI prefix factor corresponding to 10
29 public const double Deca = 1e1;30 31 /// The SI prefix factor corresponding to 0.1
32 public const double Deci = 1e-1;33 34 /// The SI prefix factor corresponding to 0.01
35 public const double Centi = 1e-2;36 37 /// The SI prefix factor corresponding to 0.001
38 public const double Milli = 1e-3;39 40 /// The SI prefix factor corresponding to 0.000 001
41 public const double Micro = 1e-6;42 43 /// The SI prefix factor corresponding to 0.000 000 001
44 public const double Nano = 1e-9;45 46 /// The SI prefix factor corresponding to 0.000 000 000 001
47 public const double Pico = 1e-12;48 49 /// The SI prefix factor corresponding to 0.000 000 000 000 001
50 public const double Femto = 1e-15;51 52 /// The SI prefix factor corresponding to 0.000 000 000 000 000 001
53 public const double Atto = 1e-18;54 55 /// The SI prefix factor corresponding to 0.000 000 000 000 000 000 001
56 public const double Zepto = 1e-21;57 58 /// The SI prefix factor corresponding to 0.000 000 000 000 000 000 000 001
59 public const double Yocto = 1e-24;

7.资源

　　源码下载：

　　如果本文资源或者显示有问题，请参考：