Re: [R] Replacing columns in a data frame using a previous condition

From: jim holtman <jholtman_at_gmail.com>
Date: Thu, 14 Feb 2008 15:41:39 -0500

Is this what you want to do?

> x <- data.frame(a=1:10, b=1:10, c=1:10, d=1:10)
> z <- cbind(c=11:20, d=11:20)

> z

       c d

 [1,] 11 11
 [2,] 12 12
 [3,] 13 13
 [4,] 14 14
 [5,] 15 15
 [6,] 16 16
 [7,] 17 17
 [8,] 18 18
 [9,] 19 19

[10,] 20 20
> x[,colnames(z)] <- z[, colnames(z)]
> x

    a b c d
1 1 1 11 11
2 2 2 12 12
3 3 3 13 13
4 4 4 14 14
5 5 5 15 15
6 6 6 16 16
7 7 7 17 17
8 8 8 18 18
9 9 9 19 19
10 10 10 20 20
>

On 2/14/08, Jorge Iván Vélez <jorgeivanvelez_at_gmail.com> wrote:
> Dear R-list,
>
> I'm working with a data frame which dimensions are
>
> > dim(GERU)
> [1] 3468 318
>
> and looks like
>
> > GERU[1:10,1:10]
> ped ind par1 par2 sex sta rs7696470 rs7696470.1 rs1032896 rs1032896.1
> 1 USA5854 2 0 0 2 1 4 4 1 1
> 2 USA5854 3 1 2 1 1 4 4 1 1
> 3 USA5854 4 1 2 2 2 1 4 1 3
> 4 USA5854 5 1 2 1 2 4 2 2 1
> 5 USA5855 1 0 0 1 1 0 0 0 0
> 6 USA5855 2 0 0 2 2 1 0 0 0
> 7 USA5855 3 1 2 1 2 0 2 0 0
> 8 USA5855 4 1 2 1 1 2 0 2 1
> 9 USA5855 5 1 2 1 2 0 1 0 0
> 10 USA5856 1 0 0 1 1 3 3 3 3
>
> What I would like to do is:
>
> 1. Identify which column (from 6 to 318) has more than 4 categories (I
> solved that). In GERU would be rs7696470 and rs7696470.1.
> 2. Using the columns in step 1, replace its entries equals to 2 for 3. For
> example, rs7696470 would be 4,4,1,4,0,1,0,3,0,3 and so on.
> 3. Once replaced the entries, I need to rewrite the columns in GERU.
>
> Here is what I've done:
>
> > # Function to identify columns with 3 or more categories
> > tx=function(x) ifelse(dim(table(x))>4,1,0)
>
> > # Identifying the columns
> > M4=apply(GUPN[,-c(1:6)],2,tx)
> > names(which(MR==1)) # Step 1
> [1] "rs335322" "rs335322.1" "rs186750" "rs186750.1"
> "rs1565901" "rs1565901.1" "rs1565902"
> [8] "rs1565902.1" "rs11131334" "rs11131334.1" "rs1948616" "
> rs1948616.1" "rs4484334" "rs4484334.1"
> [15] "rs1497921" "rs1497921.1" "rs1391320" "rs1391320.1"
> "rs1497913" "rs1497913.1" "rs996208"
> [22] "rs996208.1"
> > # Step 2
> > REPLACE=GUPN[,names(which(AR==1))]
> > RES=apply(REPLACE,2,function(x) ifelse(x==2,3,x))
> > RES[1:10,1:5]
> rs335322 rs335322.1 rs186750 rs186750.1 rs1565901
> 1 1 3 3 3 3
> 2 1 1 3 3 3
> 3 3 3 1 3 3
> 4 1 3 3 3 3
> 5 0 0 0 0 0
> 6 0 0 0 0 0
> 7 0 0 0 0 0
> 8 0 0 0 0 0
> 9 0 0 0 0 0
> 10 1 3 3 3 1
>
> Now, the problem I have is replacing the columns in GERU by the columns in
> RES (step 3). At the end the dimension of the new data set should be
> 3468x318. Any help would be greatly appreciated.
>
> Thanks you so much,
>
>
> Jorge
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
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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.
>

-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?

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Received on Thu 14 Feb 2008 - 20:45:10 GMT

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