[R] Order all the columns ascending elements on a matrix or a data frame

[arun]

Hi,

If your intention is to order the first column by ascending, then by 2nd and so on..
Try this.

 set.seed(1)
  dat1<-cbind(x=rnorm(10,5,0.5),y=runif(10,0.4),z=rnorm(10,15,0.2))
 dat1
             x         y        z
 [1,] 4.686773 0.9608231 14.99101
 [2,] 5.091822 0.5272855 14.99676
 [3,] 4.582186 0.7910043 15.18877
 [4,] 5.797640 0.4753331 15.16424
 [5,] 5.164754 0.5603324 15.11878
 [6,] 4.589766 0.6316685 15.18380
 [7,] 5.243715 0.4080342 15.15643
 [8,] 5.369162 0.6294328 15.01491
 [9,] 5.287891 0.9218145 14.60213
[10,] 4.847306 0.6042094 15.12397
 
 dat1[order(dat1[,1],dat1[,2],dat1[,3]),]
             x         y        z
 [1,] 4.582186 0.7910043 15.18877
 [2,] 4.589766 0.6316685 15.18380
 [3,] 4.686773 0.9608231 14.99101
 [4,] 4.847306 0.6042094 15.12397
 [5,] 5.091822 0.5272855 14.99676
 [6,] 5.164754 0.5603324 15.11878
 [7,] 5.243715 0.4080342 15.15643
 [8,] 5.287891 0.9218145 14.60213
 [9,] 5.369162 0.6294328 15.01491
[10,] 5.797640 0.4753331 15.16424



But, if it is like to order all the columns at once,

apply(dat1,2,sort)

             x         y        z
 [1,] 4.582186 0.4080342 14.60213
 [2,] 4.589766 0.4753331 14.99101
 [3,] 4.686773 0.5272855 14.99676
 [4,] 4.847306 0.5603324 15.01491
 [5,] 5.091822 0.6042094 15.11878
 [6,] 5.164754 0.6294328 15.12397
 [7,] 5.243715 0.6316685 15.15643
 [8,] 5.287891 0.7910043 15.16424
 [9,] 5.369162 0.9218145 15.18380
[10,] 5.797640 0.9608231 15.18877

Here, the all columns are sorted to ascending, but only problem is that the corresponding elements in each of the rows in the original dataset has also changed.


A.K.




----- Original Message -----
From: Trying To learn again <tryingtolearnagain at gmail.com>
To: r-help at r-project.org
Cc: 
Sent: Sunday, June 10, 2012 2:36 AM
Subject: [R] Order all the columns ascending elements on a matrix or a data frame

Imagine I have a csv KT.csv

I want to create a new dataframe o convert KT in a matrix and create a new
matrix with each column of KT ordered by ascending order.

I have tried to make this

b<-read.csv("KT.csv")


for(i in 1:ncol(b)){

b[,i]<-sort(b[,i])

}

But it puts a message that the number of rows doesn´t correspond.

Can someone give me a clue on how to order.

Many Thaks.

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