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Re: DisplayForm changes precission

• To: mathgroup at smc.vnet.net
• Subject: [mg47588] Re: DisplayForm changes precission
• From: "Peter Pein" <petsie at arcor.de>
• Date: Fri, 16 Apr 2004 05:22:01 -0400 (EDT)
• References: <c5lk0f$d4a$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

"Mario Drobics" <mario.drobics at scch.at> schrieb im Newsbeitrag
news:c5lk0f$d4a$1 at smc.vnet.net...
>
> I am trying to create a GridBox to display some numbers. When applying
> GridBox, however, the precission changes and the output gets unreadable.
> Any ideas why this is happening?
>
>  Code:
> (* round to prec digits *)
> NRound[x_, prec_Integer:0] := MapAll[If[NumericQ[#],
>      N[Round[#*10^prec]/(10^prec)], #] &, x];
>
> (* everything ok here *)
> NRound[array, 2] // FullForm
> List[List[
>    7.`, 0.`, 11.`, 18.`, 34.`, 1.`, 0.13`], List[7.`, 0.`, 11.`, 18.`,
> 34.`,
>      1.`, 0.13`], List[
>    9.`, 0.`, 25.`, 34.`, 18.`, 1.`, 0.17`], List[26.95`, 7.95`, 7.05`,
> 34.`,
>      18.`, 0.77`, 0.52`], List[29.`, 11.5`, 5.`, 34.`, 18.`, 0.72`,
0.56`],
>      List[31.`, 11.5`, 3.`, 34.`, 18.`, 0.73`, 0.6`]]
>
> (* this also works *)
> NRound[array /. Obj`CompResItem -> List, 2] // TableForm
> \!\(\*
>    TagBox[GridBox[{
>          {"7.`", "0.`", "11.`", "18.`", "34.`", "1.`", "0.13`"},
>          {"7.`", "0.`", "11.`", "18.`", "34.`", "1.`", "0.13`"},
>          {"9.`", "0.`", "25.`", "34.`", "18.`", "1.`", "0.17`"},
>          {"26.95`", "7.95`", "7.05`", "34.`", "18.`", "0.77`", "0.52`"},
>          {"29.`", "11.5`", "5.`", "34.`", "18.`", "0.72`", "0.56`"},
>          {"31.`", "11.5`", "3.`", "34.`", "18.`", "0.73`", "0.6`"}
>          },
>        RowSpacings->1,
>        ColumnSpacings->3,
>        RowAlignments->Baseline,
>        ColumnAlignments->{Left}],
>      Function[ BoxForm`e$,
>        TableForm[ BoxForm`e$]]]\)
>
> (* this does not work!!! *)
> GridBox[
>      NRound[array /. Obj`CompResItem -> List, 2]
>      ] // DisplayForm
...

Hi Mario.

Strange -- in version 4.0 the following simple example works perfectly:

ppii = N[Pi, 123];
GridBox[
Table[SetAccuracy[ppii, i + j]//NumberForm,
 {i, 3}, {j, 3}]]//DisplayForm

No (unwanted) changes of accuracy occur.
"NumberForm" seems to be necessary.

-- 
Peter Pein, Berlin
to write to me, start the subject with [