Re: Fourier and 0 and N

*To*: mathgroup at smc.vnet.net*Subject*: [mg4938] Re: Fourier and 0 and N*From*: Robert Knapp <rknapp>*Date*: Mon, 7 Oct 1996 02:02:10 -0400*Organization*: Wolfram Research*Sender*: owner-wri-mathgroup at wolfram.com

Michael Schaferkotter wrote: > ... > > is there something about 0 here that i am not understanding? > > this came up using Chop and Fourier. > Mathematica distinguishes between an exact zero (0) and an inexact zero (0. or 0.0). N[0] is defined to be the exact 0. In Mathematica version 2.2, Fourier only took a numerical argument. In version 3.0, which will be out soon, all of the commands above will return the Fourier transform you would expect done useing machine precision complex numbers. > Sqrt[2] > 2 returns > > Sqrt[2] > 2 > Sqrt[0] > 0 returns > > False. This is because Sqrt[0] evaluates to 0, and 0 > 0 is False, but Sqrt[2] is not a number so the comparison is not made. In Mathematica version 3.0, Sqrt[2] > 2 returns False. Rob Knapp WRI ==== [MESSAGE SEPARATOR] ====