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Re: tabulate an expression-DigitBlock bug with zero digits

  • To: mathgroup at smc.vnet.net
  • Subject: [mg94026] Re: tabulate an expression-DigitBlock bug with zero digits
  • From: Raffy <raffy at mac.com>
  • Date: Tue, 2 Dec 2008 00:42:58 -0500 (EST)
  • References: <200811301158.GAA07541@smc.vnet.net> <gh0jkg$5lu$1@smc.vnet.net>

On Dec 1, 7:00 am, Syd Geraghty <sydgerag... at me.com> wrote:
> Bob & WRI staff,
>
> This is a really small nit but there is an annoying bug using  
> DigitBlock with a set of zero digits.
>
> They do not get separated as other digits do.
>
> Evaluate
>
> > n = 25;
> > Grid[Prepend[Table[{
> >    NumberForm[N[x], {2, 1}],
> >    NumberForm[N[Erf[x], 2 n], {n + 1, n}, DigitBlock -> 5]},
> >   {x, 0, 1, 1/10}],
> >  TraditionalForm /@ {x, Erf[x]}],
> > Frame -> All]
>
> and you will see what I mean on the output of erf(0.0).
>
> There is a workaround:-
>
> To get rid of the annoying bug ("feature") that a set of zeros is not  
> split by DigitBlock copy the Table output as a Cell Expression and  
> paste without interpretation.
>
>    Edit the line of continuous zeros deleting the extra zeros and  
> replace with a "space" character.
>
>    Then copy the cell as InputText and paste the result with  
> interpretation.
>
>    That gives the desired table with the zeros seperated like the res=
t  
> of the results for each x value.
>
> This procedure is, of course, a real pain (especially if you change  
> the table a few times before you publish it say).
>
> I realise that I need a real life if I worry about such nits.
>
> However in the interest of continuous improvement of the magical  
> Mathematica system (that I am addicted to) I offer this small  
> suggestion.
>
> Cheers ... Syd
>
> Syd Geraghty B.Sc, M.Sc.
>
> sydgerag... at mac.com
>
> Mathematica 7.0.0 for Mac OS X x86 (64 - bit) (21st November, 2008)
> MacOS X V 10.5.4
> MacBook Pro 2.33 Ghz Intel Core 2 Duo  2GB RAM
>
> On Nov 30, 2008, at 3:58 AM, Bob Hanlon wrote:
>
> > n = 25;
> > Grid[Prepend[Table[{
> >    NumberForm[N[x], {2, 1}],
> >    NumberForm[N[Erf[x], 2 n], {n + 1, n}, DigitBlock -> 5]},
> >   {x, 0, 1, 1/10}],
> >  TraditionalForm /@ {x, Erf[x]}],
> > Frame -> All]

You could always cheat and do something silly like:

Unprotect[NumberForm];
NumberForm[0, {n_, f_}, ___, DigitBlock -> m_, ___] :=
  StringJoin[{"0.",  Riffle[Partition[Table["0", {f}], m, m, 1, {}], "
"]}];
Protect[NumberForm];


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