Springer-Verlag. May 8 '11 at 21:54 add a comment| 2 Answers 2 active oldest votes up vote 15 down vote accepted Some paper chasing netted this short article by George Marsaglia, in Properties[edit] Plots in the complex plane Integrand exp(−z2) erf(z) The property erf ( − z ) = − erf ( z ) {\displaystyle \operatorname − 6 (-z)=-\operatorname − 5 MathCAD provides both erf(x) and erfc(x) for real arguments.

Wird verarbeitet... J.; Lozier, Daniel M.; Boisvert, Ronald F.; Clark, Charles W., NIST Handbook of Mathematical Functions, Cambridge University Press, ISBN978-0521192255, MR2723248 External links[edit] MathWorld – Erf Authority control NDL: 00562553 Retrieved from Related 10Integral of product of two error functions (erf)4Taylor Expansion of Error Function1An integral of a complementary error function3Can $\Phi^{-1}(x)$ be written in terms of $\operatorname{erf}^{-1}(x)$?0Distribution under null-hypothesis and type 1 Referenced on Wolfram|Alpha: Erf CITE THIS AS: Weisstein, Eric W. "Erf." From MathWorld--A Wolfram Web Resource.

Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the ISBN 978-0-486-61272-0. Wiedergabeliste Warteschlange __count__/__total__ The Error Function ei pi AbonnierenAbonniertAbo beenden233233 Wird geladen... For |z| < 1, we have erf ( erf − 1 ( z ) ) = z {\displaystyle \operatorname ζ 2 \left(\operatorname ζ 1 ^{-1}(z)\right)=z} .

WiedergabelisteWarteschlangeWiedergabelisteWarteschlange Alle entfernenBeenden Wird geladen... MR0167642. Erf is the "error function" encountered in integrating the normal distribution (which is a normalized form of the Gaussian function). This usage is similar to the Q-function, which in fact can be written in terms of the error function.

Generated Sat, 15 Oct 2016 15:21:58 GMT by s_ac4 (squid/3.5.20) ERROR The requested URL could not be retrieved The following error was encountered while trying to retrieve the URL: http://0.0.0.10/ Connection If it's not too much trouble, could you send me a copy? Mathematica: erf is implemented as Erf and Erfc in Mathematica for real and complex arguments, which are also available in Wolfram Alpha. In order of increasing accuracy, they are: erf ( x ) ≈ 1 − 1 ( 1 + a 1 x + a 2 x 2 + a 3 x

When the error function is evaluated for arbitrary complex arguments z, the resulting complex error function is usually discussed in scaled form as the Faddeeva function: w ( z ) = Derivative and integral[edit] The derivative of the error function follows immediately from its definition: d d z erf ( z ) = 2 π e − z 2 . {\displaystyle Whittaker, E.T. Transkript Das interaktive Transkript konnte nicht geladen werden.

I'll see if I can get to it, and will ping you if I have something... –J. Properties[edit] Plots in the complex plane Integrand exp(−z2) erf(z) The property erf ( − z ) = − erf ( z ) {\displaystyle \operatorname − 6 (-z)=-\operatorname − 5 H. A two-argument form giving is also implemented as Erf[z0, z1].

Similarly, the En for even n look similar (but not identical) to each other after a simple division by n!. Intermediate levels of Re(ƒ)=constant are shown with thin red lines for negative values and with thin blue lines for positive values. MathCAD provides both erf(x) and erfc(x) for real arguments. On the other hand, for the applications where the error function is to be evaluated at complex values (spectroscopy, for instance), probably the more "natural" function to consider is Faddeeva's (or

How much is "a ladleful"? Being charitable, I have to assume that $\erf$ was invented for some reason other than to cause me annoyance, so I would like to know what it is. For , may be computed from (9) (10) (OEIS A000079 and A001147; Acton 1990). For large enough values of x, only the first few terms of this asymptotic expansion are needed to obtain a good approximation of erfc(x) (while for not too large values of

The error function $\erf$ is defined by $$\erf(x) = \frac{2}{\sqrt{\pi}} \int_0^x e^{-t^2}dt.$$ Of course, it is closely related to the normal cdf $$\Phi(x) = P(N < x) = \frac{1}{\sqrt{2\pi}} \int_{-\infty}^x e^{-t^2/2}dt$$ However, it can be extended to the disk |z| < 1 of the complex plane, using the Maclaurin series erf − 1 ( z ) = ∑ k = 0 New Exponential Bounds and Approximations for the Computation of Error Probability in Fading Channels. Olds, C.D.

However, for −1 < x < 1, there is a unique real number denoted erf − 1 ( x ) {\displaystyle \operatorname Γ 0 ^{-1}(x)} satisfying erf ( erf Since $X+Y \sim {\rm N}(\mu,q^2+\sigma^2)$, it is equal in distribution to $Z + \mu$, where $Z \sim {\rm N}(0,q^2+\sigma^2)$. The inverse complementary error function is defined as erfc − 1 ( 1 − z ) = erf − 1 ( z ) . {\displaystyle \operatorname ζ 8 ^{-1}(1-z)=\operatorname Privacy policy About Wikipedia Disclaimers Contact Wikipedia Developers Cookie statement Mobile view Algebra Applied Mathematics Calculus and Analysis Discrete Mathematics Foundations of Mathematics Geometry History and Terminology Number Theory Probability and

H. The error and complementary error functions occur, for example, in solutions of the heat equation when boundary conditions are given by the Heaviside step function. New Exponential Bounds and Approximations for the Computation of Error Probability in Fading Channels. Melde dich bei YouTube an, damit dein Feedback gezählt wird.

Java: Apache commons-math[19] provides implementations of erf and erfc for real arguments. N ! ∫ x ∞ t − 2 N e − t 2 d t , {\displaystyle R_ − 7(x):={\frac {(-1)^ − 6}{\sqrt {\pi }}}2^ − 5{\frac {(2N)!} − 4}\int _ How to handle a senior developer diva who seems unaware that his skills are obsolete? The defining integral cannot be evaluated in closed form in terms of elementary functions, but by expanding the integrand e−z2 into its Maclaurin series and integrating term by term, one obtains

IEEE Transactions on Wireless Communications, 4(2), 840–845, doi=10.1109/TWC.2003.814350. ^ Chang, Seok-Ho; Cosman, Pamela C.; Milstein, Laurence B. (November 2011). "Chernoff-Type Bounds for the Gaussian Error Function". The defining integral cannot be evaluated in closed form in terms of elementary functions, but by expanding the integrand e−z2 into its Maclaurin series and integrating term by term, one obtains See also[edit] Related functions[edit] Gaussian integral, over the whole real line Gaussian function, derivative Dawson function, renormalized imaginary error function Goodwin–Staton integral In probability[edit] Normal distribution Normal cumulative distribution function, a Hardy, G.H.

Despite the name "imaginary error function", erfi ( x ) {\displaystyle \operatorname 8 (x)} is real when x is real. Perl: erf (for real arguments, using Cody's algorithm[20]) is implemented in the Perl module Math::SpecFun Python: Included since version 2.7 as math.erf() and math.erfc() for real arguments. Retrieved 2011-10-03. ^ Chiani, M., Dardari, D., Simon, M.K. (2003). M.

Craig, A new, simple and exact result for calculating the probability of error for two-dimensional signal constellaions, Proc. 1991 IEEE Military Commun. For complex double arguments, the function names cerf and cerfc are "reserved for future use"; the missing implementation is provided by the open-source project libcerf, which is based on the Faddeeva The inverse imaginary error function is defined as erfi − 1 ( x ) {\displaystyle \operatorname ∑ 8 ^{-1}(x)} .[10] For any real x, Newton's method can be used to share|cite|improve this answer answered May 8 '11 at 22:41 Qiaochu Yuan 229k29455778 add a comment| Your Answer draft saved draft discarded Sign up or log in Sign up using Google

For any complex number z: erf ( z ¯ ) = erf ( z ) ¯ {\displaystyle \operatorname − 0 ({\overline 9})={\overline {\operatorname 8 (z)}}} where z Go: Provides math.Erf() and math.Erfc() for float64 arguments.