# [R] frequency

arun smartpink111 at yahoo.com
Tue Oct 23 23:07:11 CEST 2012

```Hi,
Try this:
dat1<-read.table(text="
ID    Visit
x a1
x a2
x a2
x a1
x a1
y b1
y c23
y b33
",sep="",header=TRUE,stringsAsFactors=FALSE)
cn1<-count(dat1[!duplicated(dat1),]\$ID)
colnames(cn1)<-c("ID","response")
merge(dat1,cn1,by="ID",all=TRUE)
#ID Visit response
#1  x    a1        2
#2  x    a2        2
#3  x    a2        2
#4  x    a1        2
#5  x    a1        2
#6  y    b1        3
#7  y   c23        3
#8  y   b33        3
A.K.

________________________________
From: farnoosh sheikhi <farnoosh_81 at yahoo.com>
To: arun <smartpink111 at yahoo.com>
Sent: Tuesday, October 23, 2012 4:55 PM
Subject: Re: [R] frequency

Hi there,

Thanks a lot for getting back to me. If the data has repeated visit as follow, does the code change? Therefore the response would be 2 not 3. How can I consider this problem in my code?
ID    Visit
x       a1
x      a2
xa1
y      b1
y     c23
y     b33

Thanks a lot.
Best,Farnoosh Sheikhi

________________________________
From: arun <smartpink111 at yahoo.com>
To: farnoosh sheikhi <farnoosh_81 at yahoo.com>
Cc: R help <r-help at r-project.org>
Sent: Tuesday, October 23, 2012 1:33 PM
Subject: Re: [R] frequency

Hi,
Assuming that there are two columns in your data.
dat1<-read.table(text="
ID    Visit
x a1
x a2
y b1
y c23
y b33
",sep="",header=TRUE,stringsAsFactors=FALSE)

cnt<-count(dat1\$ID)
colnames(cnt)<-c("ID","response")
merge(dat1,cnt,by="ID",all=TRUE)
#  ID Visit response
#1  x    a1        2
#2  x    a2        2
#3  y    b1        3
#4  y   c23        3
#5  y   b33        3

But, if there is only column and you want to split
it
ID<-c("xa1","xa2","yb1","yc23","yb33")
ID1<-gsub("(.*)a.*|b.*|c.*","\\1",ID)
visit<-gsub(".*(a.*|b.*|c.*)","\\1",ID)
dat2<-data.frame(ID1,visit)
dat2[]<-lapply(dat2,as.character)

cnt<-count(dat2\$ID1)
colnames(cnt)<-c("ID1","response")
merge(dat2,cnt,by="ID1",all=TRUE)
#  ID1 visit response
#1   x    a1        2
#2   x    a2        2
#3   y    b1        3
#4   y   c23        3
#5   y   b33        3

A.K.

----- Original Message -----
From: farnoosh sheikhi <farnoosh_81 at yahoo.com>
To: "r-help at R-project.org" <r-help at r-project.org>
Cc:
Sent: Tuesday, October 23, 2012 3:14 PM
Subject: [R] frequency

Hello,

I have a data as follow:
ID    Visit
xa1
xa2
yb1
yc23
yb33

I want to look at frequency of visit for ID and create a new column as response .
For example my response would be 2 for x and 3 for y.
I think I need to write a loop, but I don't know how.
I really appreciate your help.
Thanks a lot.
Best,Farnoosh Sheikhi
[[alternative HTML version deleted]]

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