R help - Sep 2009 - selecting columns based on values of two variables

Dear R-list,

I am having troubles selecting rows from a very large data-set  
containing distances between capitals.

The structure of the data-set looks like this:

      	numa 	ida 		numb 	idb 		kmdist 	midist
1        2 		USA   	20 		CAN    	731    	456
2        2	 	USA   	31 		BHM   	1623   	1012
3        2 		USA   	40 		CUB   	1813   	1130


I want to select a subset of these dyads, and have tried the following  
code:

subset(capdist,ida == c("DEN","SWD","FIN") &
idb ==
c("DEN","SWD","FIN"))

This should ideally give me the dyads involving only Denmark, Sweden  
and Finland, however i get the error message:

[1] numa   ida    numb   idb    kmdist midist
<0 rows> (or 0-length row.names)
Warning messages:
1: In is.na(e1) | is.na(e2) :
   longer object length is not a multiple of shorter object length
2: In `==.default`(ida, c("DEN", "SWD", "FIN")) :
   longer object length is not a multiple of shorter object length
3: In is.na(e1) | is.na(e2) :
   longer object length is not a multiple of shorter object length
4: In `==.default`(idb, c("DEN", "SWD", "FIN")) :
   longer object length is not a multiple of shorter object length

Any help would be greatly appreciated,

Best, Thomas Jensen
	[[alternative HTML version deleted]]

probably you're looking for

subset(capdist, ida %in% c("DEN","SWD","FIN")
& idb %in%
c("DEN","SWD","FIN"))


I hope it helps.

Best,
Dimitris


Thomas Jensen wrote:
> Dear R-list,
> 
> I am having troubles selecting rows from a very large data-set  
> containing distances between capitals.
> 
> The structure of the data-set looks like this:
> 
>       	numa 	ida 		numb 	idb 		kmdist 	midist
> 1        2 		USA   	20 		CAN    	731    	456
> 2        2	 	USA   	31 		BHM   	1623   	1012
> 3        2 		USA   	40 		CUB   	1813   	1130
> 
> 
> I want to select a subset of these dyads, and have tried the following  
> code:
> 
> subset(capdist,ida == c("DEN","SWD","FIN")
& idb ==
> c("DEN","SWD","FIN"))
> 
> This should ideally give me the dyads involving only Denmark, Sweden  
> and Finland, however i get the error message:
> 
> [1] numa   ida    numb   idb    kmdist midist
> <0 rows> (or 0-length row.names)
> Warning messages:
> 1: In is.na(e1) | is.na(e2) :
>    longer object length is not a multiple of shorter object length
> 2: In `==.default`(ida, c("DEN", "SWD",
"FIN")) :
>    longer object length is not a multiple of shorter object length
> 3: In is.na(e1) | is.na(e2) :
>    longer object length is not a multiple of shorter object length
> 4: In `==.default`(idb, c("DEN", "SWD",
"FIN")) :
>    longer object length is not a multiple of shorter object length
> 
> Any help would be greatly appreciated,
> 
> Best, Thomas Jensen
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
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> PLEASE do read the posting guide
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> 
-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

Dear R-list,

Sorry for spamming the list, but I am just learning how to manipulate  
data in R, so  if this is a trivial question I am sorry.

I have the following data which list the distance between capitals:

       		ida   	idb   	kmdist
7108  	"UK"  	"BEL" 	" 313"
7110	"UK"  	"FRN" 	" 365"
7116  	"UK"  	"POR" 	"1618"

I would like to convert this into an a valued adjacency matrix that  
looks like this:

	BEL		FRN	POR
UK	313		365		1618

The full data set has all possible pairings between countries, so the  
end goal should be a symmetric adjacency matrix.

Thank you,

Thomas Jensen