Re: RealDigits bug?

*To*: mathgroup at smc.vnet.net*Subject*: [mg45871] Re: RealDigits bug?*From*: adam.smith at hillsdale.edu (Adam Smith)*Date*: Wed, 28 Jan 2004 05:19:09 -0500 (EST)*References*: <bv00g1$je7$1@smc.vnet.net> <bv2g1t$68$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Bobby, What version of Mathematica are you using? I am running Version 4.1 and it does not include 10 in the Frequencies list In[3]:= Frequencies[First[RealDigits[ pisot]]] Out[3]= {{2089,0},{422,1},{427,2},{434,3},{467,4},{444,5},{452,6},{447,7},{437, 8},{381,9}} In response to Enrique. I suspect that the failure is related to a misunderstanding of the N[] function. In particular look in the Help for N[] and study the $MaxMachineNumber and $MaxPrecision. Since your pisot is on the order of 10^3340, you may be running into truncation errors with N[]. On my machine $MaxMachineNumber is around 10^308. Since pisot is clearly much greater than this, I would expect truncation errors. Adam Smith drbob at bigfoot.com (Bobby R. Treat) wrote in message news:<bv2g1t$68$1 at smc.vnet.net>... > I don't know whether the equality should be true, but it's very clear > that 10 isn't a base-10 digit! > > Frequencies[First[RealDigits[ > pisot]]] > {{2086, 0}, {422, 1}, > {427, 2}, {434, 3}, > {467, 4}, {444, 5}, > {452, 6}, {447, 7}, > {437, 8}, {381, 9}, {3, 10}} > > Bobby > > Enrique Zeleny <ezeleny at fismat1.fcfm.buap.mx> wrote in message news:<bv00g1$je7$1 at smc.vnet.net>... > > This is wrong: > > > > In[1]:= pisot = N[((1/3)*((1/2)*(27 + 3*Sqrt[69]))^(1/3) + (2/(27 + > > 3*Sqrt[69]))^(1/3))^27351, 6000]; > > > > In[2]:= pisot == FromDigits[RealDigits[pisot]] > > > > Out[2]:= False > > > > If you look at the value returned by RealDigits[pisot] contains three > > 10's!!! > > > > > > Enrique Zeleny > > Universidad Autonoma de Puebla > > Mexico