3.5.1.3 Special Math


Contents

Airy

Name Brief
Evaluates an approximation to the Airy function, Ai(x).
Evaluates an approximation to the derivative of the Airy function Ai(x).
Evaluates an approximation to the Airy function Bi(x).
Evaluates an approximation to the derivative of the Airy function Bi(x).

Bessel

Name Brief
Evaluates an approximation to the modified Bessel function of the first kind I\(\nu\)/4 (x)
Evaluates an approximation to the modified Bessel function of the first kind \(e^{-x}I_{\frac \nu 4}(x)\)
Evaluates an approximation to the modified Bessel function of the first kind, I0(x).
Evaluates an approximation to \(e^{-|x|}I_0(x)\)
Evaluates an approximation to the modified Bessel function of the first kind,\(I_1(x)\).
Evaluates an approximation to \(e^{-|x|}I_1(x)\)
Evaluates the Bessel function of the first kind,\(J_0(x)\)
Evaluates an approximation to the Bessel function of the first kind \(J_1(x)\)
Evaluates an approximation to the modified Bessel function of the second kind \(K_{\upsilon /4}(x)\)
Evaluates an approximation to the modified Bessel function of the second kind \(e^{-x}K_{\upsilon /4}(x)\)
Evaluates an approximation to the modified Bessel function of the second kind,\(K_0\left( x\right)\)
Evaluates an approximation to \(e^xK_0\left( x\right)\)
Evaluates an approximation to the modified Bessel function of the second kind,\(K_1\left( x\right) \)
Evaluates an approximation to \(e^xK_1\left( x\right)\)
Evaluates the Bessel function of the second kind,\(Y_0\) , x > 0.
Evaluates the Bessel function of the second kind,\(Y_1\) , x > 0.
Modified Bessel function of first kind
Bessel function of first kind
Modified Bessel function of second kind
Bessel function of second kind
Bessel function of order n
Bessel Function of Second Kind
First Order Bessel Function
First order Bessel function of second kind has the following form: Y1(x)
Zero Order Bessel Function
Zero Order Bessel Function of Second Kind

Beta

Name Brief
Beta Function
Incomplete Beta Function

Error

Name Brief
An error function calculated by \(\mathrm{erf}(x)=\frac{2}{\sqrt\pi}\int_{0}^{x}e^{-u^2}du\)
Calculates an approximate value for the complement of the error function \(erfc(x)=\frac 1{\sqrt{\pi }}\int_x^\infty e^{\frac{-u^2}2}du=1-{erf(x)}\)
Computes the value of the inverse complementary error function for specified y
An scaled complementary error function calculated by \(erfcx(x) = e^{x^2}\cdot erfc(x)\)
Calculates the inverse of error function \(erf\)

Gamma

Name Brief
Evaluates \(\Gamma (x)=\int_0^\infty t^{x-1}e^{-t}dt\)
Evaluates the incomplete gamma functions in the normalized form \(P(a,x)=\frac 1{\Gamma (a)}\int_0^xt^{a-1}e^{-t}dt\)
Evaluates \(\ln \Gamma (x)\), x > 0.
Evaluates an approximation to the kth derivative of the psi function \(\psi (x)\) by \(\Psi ^k(x)=\frac{d^k}{dx^k}\Psi (x)=\frac{d^k}{dx^k}(\frac d{dx^k}\log _e\Gamma (x))\) where x is real with x≠0, -1, -2, ... and k=0,1,......6.
Incomplete gamma functions
Natural Log of the Gamma Function
Calculate the incomplete Gamma function

Integral

Name Brief
Evaluates an approximation of \(C_i\left( x\right) =y+\ln x+\int_0^x\frac{\cos u-1}udu\).
Evaluates the cumulative Normal distribution function \(P(x)=\frac 1{\sqrt{2\pi }}\int_{-\infty }^xe^{\frac{-u^2}2}du\)
Evaluates an approximate value for the complement of the cumulative normal distribution function \(Q(x)=\frac 1{\sqrt{2\pi }}\int_x^\infty e^{\frac{-u^2}2}du\)
calculates an approximate value for the integral \(R_c(x,y)=\frac 12\int_0^\infty \frac{dt}{\sqrt{t+x}(t+y)}\) where x ≥ 0 and y ≠ 0.
Calculates an approximate value for the integral \(R_D(x,y,z)=\frac 32\int_0^\infty \frac{dt}{\sqrt{(t+z)(t+y)(t+z)^3}}\) .
Calculates an approximation to the integral \(R_F(x,y,z)=\frac 12\int_0^\infty \frac{dt}{\sqrt{(t+x)(t+y)(t+z)}}\) .
Calculates an approximation to the integral \(R_J(x,y,z,\rho )=\frac 32\int_0^\infty \frac{dt}{(t+\rho )\sqrt{(t+x)(t+y)(t+z)}}\).
Evaluates \(E_1(x)=\int_x^\infty \frac{e^{-u}}udu \), x>0.
Evaluates an approximation to the Fresnel Integral \(S(x)=\int_0^x\cos (\frac \pi 2t^2)dt\).
Evaluates an approximation to the Fresnel Integral \(S(x)=\int_0^x\sin (\frac \pi 2t^2)dt\).
Evaluates the approximation of the formula \(Si(x)=\int_0^x\frac{\sin u}udu\)

Kelvin

Name Brief
Evaluates an approximation to the Kelvin function bei x.
Evaluates an approximation to the Kelvin function ber x.
Evaluates an approximation to the Kelvin function kei x.
Evaluates an approximation to the Kelvin function ker x.

Miscellaneous

Name Brief
Evaluates an approximation to the Jacobian theta functions.
Evaluates an approximate value for the real branches of Lambert’s W function.
Boltzmann Function
Double Rectangular Hyperbola Function
Exponential Associate Function
Exponential Decay 2 with Offset Function
Exponential Growth 2 with Offset Function
Gaussian Function
Hyperbola Function
Logistic Dose Response Function
Lorentzian Function
Polynomial Function
Pulse Function
Lambert’s W function (sometimes known as the ‘product log’ or ‘Omega’ function)
Complementary error function