erf

Contents: Description, Arguments, Usage, Examples, Sub-Functions, Related Functions, Source Supported Under Version: > 1.10 Current .dvrc Version: 1.29 Description Error function Arguments and Return Values Arguments: One numeric array Return Value: An array with the same organization as the input containing the value of the error function evaluated at the each element of the input. The output format is double if the input is double, float otherwise. The error function is defined as erf(x) = integral from 0 to x of exp(-t^2)*2/√π with respect to t This function uses a numerical approximation from W. J. Cody and Peter J. Acklam, which is accurate within the precision of the input. If no arguments are input, erf() prints its description, as shown below. Usage Syntax: erf(x) 'x' - A numeric array of any format Examples dv> erf() Error function erf(x) = integral from 0 to x of exp(-t^2)*2/sqrt(pi) Works for arrays Accurate within precision of input Uses algorithm from W. J. Cody and Peter J. Acklam See http://www.jstor.org/view/00255718/di970531/97p03754/0, http://search.cpan.org/src/REID/Games-Go-GoPair-1.001/Erf.pm, and http://www.netlib.org/specfun/erf S.Marshall 02-17-2008 0 dv> erf(-1//0//1) 3x1x1 array of float, bsq format [12 bytes] -0.842701 0.00000 0.842701

DavinciWiki Mini-Nav Bar Contents Functions Function Categories Common Procedures Glossary Download Davinci Change Log News Mailing List Contact Developers davinci-dev [AT] mars.asu.edu All other topics See navigation on the left Major Sub-Functions atod dim format isnum sign Related Functions exp inverf normcdf math.dvrc erf() Recent Library Changes Change Log Created On: 02-21-2008 Modified On: 02-22-2008