R help - Feb 2008 - How to handle Which on two matrices that do not have same number of rows

R-newbie question

 

I have 2 matrices 

(a)   P1 has only one column of 32K rows

(b)   PC  has 2 column {P, C} of 3200 rows

 

Every values in P1 matches with a value in PC[,p] (column p).  I would like
to use Which to search for all value in P1 that matchex PC[,p] and get the
PC[,c].  However because P1 and PC does not have the same number of rows, I
got lots of 'NA'.  Thanks for your help.

 

Example.. 

 

P1 <- {'p001', 'p001', 'p002', 'p010'..}

PC <- { c('p001','class a'), c('p002', 'class
b'),.. , c('p010', 'class
10')}

 

Result <- {c('p001', 'class a'), c('p001', 'class
a'), c ('p002', 'class
b'), c('p010', 'class 10')...}

 

 

My D. Coyne

 

 

 


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Try this:

merge(data.frame(P1), data.frame(PC), by.x=1, by.y=1)

On 13/02/2008, My Coyne <mcoyne at boninc.com>
wrote:
> R-newbie question
>
>
>
> I have 2 matrices
>
> (a)   P1 has only one column of 32K rows
>
> (b)   PC  has 2 column {P, C} of 3200 rows
>
>
>
> Every values in P1 matches with a value in PC[,p] (column p).  I would like
> to use Which to search for all value in P1 that matchex PC[,p] and get the
> PC[,c].  However because P1 and PC does not have the same number of rows, I
> got lots of 'NA'.  Thanks for your help.
>
>
>
> Example..
>
>
>
> P1 <- {'p001', 'p001', 'p002', 'p010'..}
>
> PC <- { c('p001','class a'), c('p002',
'class b'),.. , c('p010', 'class
> 10')}
>
>
>
> Result <- {c('p001', 'class a'), c('p001',
'class a'), c ('p002', 'class
> b'), c('p010', 'class 10')...}
>
>
>
>
>
> My D. Coyne
>
>
>
>
>
>
>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

How about this?

PC[na.omit(match(P1[,1],PC[,1])),]

HTH,

DYH

-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org]On Behalf Of My Coyne
Sent: February 13, 2008 2:07 PM
To: r-help at stat.math.ethz.ch
Subject: [R] How to handle Which on two matrices that do not have
samenumber of rows


R-newbie question



I have 2 matrices

(a)   P1 has only one column of 32K rows

(b)   PC  has 2 column {P, C} of 3200 rows



Every values in P1 matches with a value in PC[,p] (column p).  I would like
to use Which to search for all value in P1 that matchex PC[,p] and get the
PC[,c].  However because P1 and PC does not have the same number of rows, I
got lots of 'NA'.  Thanks for your help.



Example..



P1 <- {'p001', 'p001', 'p002', 'p010'..}

PC <- { c('p001','class a'), c('p002', 'class
b'),.. , c('p010', 'class
10')}



Result <- {c('p001', 'class a'), c('p001', 'class
a'), c ('p002', 'class
b'), c('p010', 'class 10')...}





My D. Coyne








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______________________________________________
R-help at r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.