[R] aggregate function....

[Stephane CRUVEILLER]

Nice trick, thx...

Stéphane.

On Wed, 2006-03-29 at 11:17 -0500, jim holtman wrote:
> try 'by':
>  
> > x
>       S_id AF_Class count... R_gc_percent S_length
> 5  8264497        1       30         0.48    35678
> 6  8264497        3        7         0.48    35678
> 8  8264554        1       31         0.51    38894 
> 9  8264554        2       11         0.51    38894
> 10 8264554        3        1         0.51    38894
> > do.call('rbind', by(x, x$S_id, function(y) y[which.max(y
> $AF_Class),]))
>            S_id AF_Class count... R_gc_percent S_length 
> 8264497 8264497        3        7         0.48    35678
> 8264554 8264554        3        1         0.51    38894
> > 
> 
> 
>  
> On 3/29/06, Stephane CRUVEILLER <scruveil at genoscope.cns.fr> wrote: 
>         Dear R users,
>         
>         I have some trouble with the aggregate function. Here are my
>         data
>         
>         > daf
>              S_id AF_Class count... R_gc_percent S_length
>         5  8264497        1       30         0.48    35678
>         6  8264497        3        7         0.48    35678
>         8  8264554        1       31         0.51    38894
>         9  8264554        2       11         0.51    38894
>         10 8264554        3        1         0.51    38894
>         
>         for a given S_id, I would like to select the line
>         corresponding to the
>         max count. To perform this, I used:
>         > aggregate(daf,list(daf$S_id),max) 
>         Group.1    S_id AF_Class count... R_gc_percent S_length
>         1 8264497 8264497        3       30         0.48    35678
>         2 8264554 8264554        3       31         0.51    38894
>         
>         which is ok for the count. But I realized that max function is
>         also 
>         applied
>         to AF_class (should be 1 and 1 instead of 3 and 3), so it
>         seems that
>         aggregate is not the appropriate function for that I want to
>         do. Is
>         there any other function I could use instead?
>         
>         Best whishes, 
>         
>         
>         Stéphane.
>         --
>         ==========================================================
>         Stephane CRUVEILLER Ph. D.
>         Genoscope - Centre National de Sequencage
>         Atelier de Genomique Comparative
>         2, Rue Gaston Cremieux   CP 5706 
>         91057 Evry Cedex - France
>         Phone: +33 (0)1 60 87 84 58
>         Fax: +33 (0)1 60 87 25 14
>         EMails: scruveil at genoscope.cns.fr ,scruvell at infobiogen.fr
>         
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> 
> 
> -- 
> Jim Holtman
> Cincinnati, OH 
> +1 513 646 9390 (Cell)
> +1 513 247 0281 (Home)
> 
> What the problem you are trying to solve? 
-- 
==========================================================
Stephane CRUVEILLER Ph. D.
Genoscope - Centre National de Sequencage
Atelier de Genomique Comparative
2, Rue Gaston Cremieux   CP 5706
91057 Evry Cedex - France
Phone: +33 (0)1 60 87 84 58
Fax: +33 (0)1 60 87 25 14
EMails: scruveil at genoscope.cns.fr ,scruvell at infobiogen.fr