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functions_overview.md

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Functions

Here the Special Functions are listed according to the structure of NIST Digital Library of Mathematical Functions.

Function Description
[gamma(z)](@ref SpecialFunctions.gamma(::Number)) gamma function \Gamma(z)
[loggamma(x)](@ref SpecialFunctions.loggamma(::Number)) accurate log(gamma(x)) for large x
[logabsgamma(x)](@ref SpecialFunctions.logabsgamma) accurate log(abs(gamma(x))) for large x
[logfactorial(x)](@ref SpecialFunctions.logfactorial) accurate log(factorial(x)) for large x; same as loggamma(x+1) for x > 1, zero otherwise
[digamma(x)](@ref SpecialFunctions.digamma) digamma function (i.e. the derivative of loggamma at x)
[invdigamma(x)](@ref SpecialFunctions.invdigamma) invdigamma function (i.e. inverse of digamma function at x using fixed-point iteration algorithm)
[trigamma(x)](@ref SpecialFunctions.trigamma) trigamma function (i.e the logarithmic second derivative of gamma at x)
[polygamma(m,x)](@ref SpecialFunctions.polygamma) polygamma function (i.e the (m+1)-th derivative of the loggamma function at x)
[gamma(a,z)](@ref SpecialFunctions.gamma(::Number,::Number)) upper incomplete gamma function \Gamma(a,z)
[loggamma(a,z)](@ref SpecialFunctions.loggamma(::Number,::Number)) accurate log(gamma(a,x)) for large arguments
[gamma_inc(a,x,IND)](@ref SpecialFunctions.gamma_inc) incomplete gamma function ratio P(a,x) and Q(a,x) (i.e evaluates P(a,x) and Q(a,x)for accuracy specified by IND and returns tuple (p,q))
[beta_inc(a,b,x,y)](@ref SpecialFunctions.beta_inc) incomplete beta function ratio Ix(a,b) and Iy(a,b) (i.e evaluates Ix(a,b) and Iy(a,b) and returns tuple (p,q))
[gamma_inc_inv(a,p,q)](@ref SpecialFunctions.gamma_inc_inv) inverse of incomplete gamma function ratio P(a,x) and Q(a,x) (i.e evaluates x given P(a,x)=p and Q(a,x)=q
[beta(x,y)](@ref SpecialFunctions.beta) beta function at x,y
[logbeta(x,y)](@ref SpecialFunctions.logbeta) accurate log(beta(x,y)) for large x or y
[logabsbeta(x,y)](@ref SpecialFunctions.logabsbeta) accurate log(abs(beta(x,y))) for large x or y
[logabsbinomial(x,y)](@ref SpecialFunctions.logabsbinomial) accurate log(abs(binomial(n,k))) for large n and k near n/2
[binomial(x,y)](@ref Base.binomial) generalized binomial coefficient { x \choose y} for x,y \in \mathbb{C}
Function Description
[expint(ν, z)](@ref SpecialFunctions.expint) exponential integral \operatorname{E}_\nu(z)
[expinti(x)](@ref SpecialFunctions.expinti) exponential integral \operatorname{Ei}(x)
[expintx(x)](@ref SpecialFunctions.expintx) exponential integral e^z \operatorname{E}_\nu(z)
[sinint(x)](@ref SpecialFunctions.sinint) sine integral \operatorname{Si}(x)
[cosint(x)](@ref SpecialFunctions.cosint) cosine integral \operatorname{Ci}(x)
Function Description
[erf(x)](@ref SpecialFunctions.erf) error function at x
[erf(x,y)](@ref SpecialFunctions.erf) accurate version of \operatorname{erf}(y) - \operatorname{erf}(x)
[erfc(x)](@ref SpecialFunctions.erfc) complementary error function, i.e. the accurate version of 1-\operatorname{erf}(x) for large x
[erfcinv(x)](@ref SpecialFunctions.erfcinv) inverse function to [erfc()](@ref SpecialFunctions.erfc)
[erfcx(x)](@ref SpecialFunctions.erfcx) scaled complementary error function, i.e. accurate e^{x^2} \operatorname{erfc}(x) for large x
[logerfc(x)](@ref SpecialFunctions.logerfc) log of the complementary error function, i.e. accurate \operatorname{ln}(\operatorname{erfc}(x)) for large x
[logerfcx(x)](@ref SpecialFunctions.logerfcx) log of the scaled complementary error function, i.e. accurate \operatorname{ln}(\operatorname{erfcx}(x)) for large negative x
[erfi(x)](@ref SpecialFunctions.erfi) imaginary error function defined as -i \operatorname{erf}(ix)
[erfinv(x)](@ref SpecialFunctions.erfinv) inverse function to [erf()](@ref SpecialFunctions.erf)
[dawson(x)](@ref SpecialFunctions.dawson) scaled imaginary error function, a.k.a. Dawson function, i.e. accurate \frac{\sqrt{\pi}}{2} e^{-x^2} \operatorname{erfi}(x) for large x
Function Description
[airyai(z)](@ref SpecialFunctions.airyai) Airy Ai function at z
[airyaiprime(z)](@ref SpecialFunctions.airyaiprime) derivative of the Airy Ai function at z
[airybi(z)](@ref SpecialFunctions.airybi) Airy Bi function at z
[airybiprime(z)](@ref SpecialFunctions.airybiprime) derivative of the Airy Bi function at z
[airyaix(z)](@ref SpecialFunctions.airyaix), [airyaiprimex(z)](@ref SpecialFunctions.airyaiprimex), [airybix(z)](@ref SpecialFunctions.airybix), [airybiprimex(z)](@ref SpecialFunctions.airybiprimex) scaled Airy Ai function and kth derivatives at z
Function Description
[besselj(nu,z)](@ref SpecialFunctions.besselj) Bessel function of the first kind of order nu at z
[besselj0(z)](@ref SpecialFunctions.besselj0) besselj(0,z)
[besselj1(z)](@ref SpecialFunctions.besselj1) besselj(1,z)
[besseljx(nu,z)](@ref SpecialFunctions.besseljx) scaled Bessel function of the first kind of order nu at z
[sphericalbesselj(nu,z)](@ref SpecialFunctions.sphericalbesselj) Spherical Bessel function of the first kind of order nu at z
[bessely(nu,z)](@ref SpecialFunctions.bessely) Bessel function of the second kind of order nu at z
[bessely0(z)](@ref SpecialFunctions.bessely0) bessely(0,z)
[bessely1(z)](@ref SpecialFunctions.bessely1) bessely(1,z)
[besselyx(nu,z)](@ref SpecialFunctions.besselyx) scaled Bessel function of the second kind of order nu at z
[sphericalbessely(nu,z)](@ref SpecialFunctions.sphericalbessely) Spherical Bessel function of the second kind of order nu at z
[besselh(nu,k,z)](@ref SpecialFunctions.besselh) Bessel function of the third kind (a.k.a. Hankel function) of order nu at z; k must be either 1 or 2
[hankelh1(nu,z)](@ref SpecialFunctions.hankelh1) besselh(nu, 1, z)
[hankelh1x(nu,z)](@ref SpecialFunctions.hankelh1x) scaled besselh(nu, 1, z)
[hankelh2(nu,z)](@ref SpecialFunctions.hankelh2) besselh(nu, 2, z)
[hankelh2x(nu,z)](@ref SpecialFunctions.hankelh2x) scaled besselh(nu, 2, z)
[besseli(nu,z)](@ref SpecialFunctions.besseli) modified Bessel function of the first kind of order nu at z
[besselix(nu,z)](@ref SpecialFunctions.besselix) scaled modified Bessel function of the first kind of order nu at z
[besselk(nu,z)](@ref SpecialFunctions.besselk) modified Bessel function of the second kind of order nu at z
[besselkx(nu,z)](@ref SpecialFunctions.besselkx) scaled modified Bessel function of the second kind of order nu at z
[jinc(x)](@ref SpecialFunctions.jinc) scaled Bessel function of the first kind divided by x. A.k.a. sombrero or besinc
Function Description
[ellipk(m)](@ref SpecialFunctions.ellipk) complete elliptic integral of 1st kind K(m)
[ellipe(m)](@ref SpecialFunctions.ellipe) complete elliptic integral of 2nd kind E(m)
Function Description
[eta(x)](@ref SpecialFunctions.eta) Dirichlet eta function at x
[zeta(x)](@ref SpecialFunctions.zeta) Riemann zeta function at x