[R] Fast Removing Duplicates from Every Column

[Petr Pikal]

Hi

I am not sure if I understand how do you want to select unique items.

with
 sapply(DF, function(x) !duplicated(x))
you can get data frame with TRUE when an item in particular column is 
unique and FALSE in opposite. However then you need to choose which 
rows to keep or discard

e.g.

DF[rowSums(sapply(comp, function(x) !duplicated(x)))>1,]

selects all rows in which are 2 or more unique values.

HTH
Petr


On 5 Jan 2007 at 9:54, Bert Jacobs wrote:

From:           	"Bert Jacobs" <b.jacobs at pandora.be>
To:             	"'R help list'" <r-help at stat.math.ethz.ch>
Date sent:      	Fri, 5 Jan 2007 09:54:17 +0100
Subject:        	Re: [R] Fast Removing Duplicates from Every Column

> Hi,
> 
> I'm looking for some lines of code that does the following:
> I have a dataframe with 160 Columns and a number of rows (max 30):
> 
>   Col1 Col2 Col3 ... Col 159 Col 160 
> Row 1 	0 	0 	LD ... 0	   VD 
> Row 2 	HD 	0 	0 	 0 	   MD 
> Row 3 	0 	HD 	HD 	 0       LD 
> Row 4 	LD 	HD 	HD 	 0 	   LD 
> ...		...
> LastRow	HD    HD    LD     0       MD
> 
> 
> Now I want a dataframe that looks like this. As you see all duplicates
> are removed. Can this dataframe be constructed in a fast way?
> 
>   Col1 Col2 Col3 ... Col 159 Col 160 
> Row 1       0    0    LD       0	    VD
> Row 2     	HD   HD   0        0        MD
> Row 3     	LD   0    HD       0        LD
> 
> Thx for helping me out.
> Bert
> 
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Petr Pikal
petr.pikal at precheza.cz