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Topic: R: R: ReplacePart -> eliminate
Replies: 4   Last Post: Sep 19, 2013 1:14 AM

 Messages: [ Previous | Next ]
 Bob Hanlon Posts: 906 Registered: 10/29/11
Re: R: ReplacePart -> eliminate
Posted: Sep 18, 2013 6:14 AM

y = Table[{n, 1/(3 - n)}, {n, 0, 5}] // Quiet

{{0, 1/3}, {1, 1/2}, {2, 1},
{3, ComplexInfinity},
{4, -1}, {5, -(1/2)}}

Note that your crtiteria in the Select does not produce a straight True or
False

{NumberQ[#], NumberQ[#]} &[{2, 1}]

{False, False}

num = Select[y, And @@ NumericQ /@ # &]

{{0, 1/3}, {1, 1/2}, {2, 1},
{4, -1}, {5, -(1/2)}}

However, Cases is a better choice here

num ==
Cases[y, _?(And @@ NumericQ /@ # &)] ==
Cases[y, {_?NumericQ, _?NumericQ}] ==
Cases[y, {_?NumericQ ..}]

True

Bob Hanlon

On Tue, Sep 17, 2013 at 9:36 PM, Brambilla Roberto Luigi (RSE) <
Roberto.Brambilla@rse-web.it> wrote:

> Great!
> Many thanks Alexei!
> Now I have the following list of couples
>
> y = Table[{n, 1/(3 - n)}, {n, 0, 5}]
>
> {{0, 1/3}, {1, 1/2}, {2, 1}, {3, ComplexInfinity}, {4, -1}, {5, -(1/2)}}
>
> The command
>
> Select[y, {NumberQ[#], NumberQ[#]} &]
>
> does not work. How can I modify your suggestion in order to eliminate the
> non-numerical couple {3,ComplexInfinity}
> from the list (avoiding Transpose etc..)?
>
> Rob.
>
>
> -----Messaggio originale-----
> Da: Alexei Boulbitch [mailto:Alexei.Boulbitch@iee.lu]
> Inviato: marted=EC 17 settembre 2013 09:09
> A: mathgroup@smc.vnet.net
> Cc: Brambilla Roberto Luigi (RSE)
> Oggetto: Re: ReplacePart -> eliminate
>
> I'd like to eliminate the Indeterminate (or other non-numerical terms, as
> Infinite, etc...) items. Es.
>
>
> x = {-1.25664, 0.628319, -0.628319, 1.25664, Indeterminate, -1.25664,
> 0.628319, -0.628319, 1.25664, Indeterminate};
>
> or
>
> x=Table[1/(3 - n), {n, 0, 5}])
> {1/3, 1/2, 1, ComplexInfinity, -1,-1/2}
>
> How can I do it with a simple command?
> Many thanks, Roberto
>
>
> Hi, Roberto,
>
> Try this:
>
> x = {-1.25664, 0.628319, -0.628319, 1.25664, Indeterminate, -1.25664,
> 0.628319, -0.628319, 1.25664, Indeterminate}; y = Table[1/(3 - n), {n,
> 0, 5}];
>
> Select[x, NumberQ[#] &]
> Select[y, NumberQ[#] &]
>
> {-1.25664, 0.628319, -0.628319, 1.25664, -1.25664, 0.628319, \ -0.628319,
> 1.25664}
>
> {1/3, 1/2, 1, -1, -(1/2)}
>
> Have fun, Alexei
>
> Alexei BOULBITCH, Dr., habil.
> IEE S.A.
> ZAE Weiergewan,
> 11, rue Edmond Reuter,
> L-5326 Contern, LUXEMBOURG
>
> Office phone : +352-2454-2566
> Office fax: +352-2454-3566
> mobile phone: +49 151 52 40 66 44
>
> e-mail: alexei.boulbitch@iee.lu
>
>
>
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Date Subject Author
9/18/13 Brambilla Roberto Luigi (RSE)
9/18/13 Bob Hanlon
9/19/13 Bob Hanlon