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Subsetting a group of data

5 messages · Ian Arvin, R. Michael Weylandt, Rui Barradas +1 more

R. Michael Weylandt
#
On Thu, Oct 4, 2012 at 3:20 PM, Ian Arvin <ian at innovativequant.com> wrote:
Up it hopefully, no?
Short answer is to ask why you want to do this? There are many
functions which operate on the split-->apply-->combine paradigm (see
the JSS article of that name for a short intro) but I find it easier
to do this in conjunction with specifying what my data transformation
is.

To directly answer your question, you'll probably need to combine
split() and interaction() in some way.

Cheers,
Michael
Rui Barradas
# 
Hello,

Try the following.


dat <- read.table(text="
Cola       Colb
1              1              1
2              1              1
3              1              1
4              -1            1
5              -1            -1
6              -1            -1
7              1              -1
8              -1            -1
9              -1            -1
10           -1            -1
", header=TRUE)

idx <- dat$Cola != dat$Colb
split(dat, 2*cumsum(idx) - idx)


Hope this helps,

Rui Barradas
Em 04-10-2012 15:20, Ian Arvin escreveu:
arun
# 
Hi,
You can also try this:
dat1 <- read.table(text="
Cola?????? Colb
1????????????? 1????????????? 1
2????????????? 1????????????? 1
3????????????? 1????????????? 1
4????????????? -1??????????? 1
5????????????? -1??????????? -1
6????????????? -1??????????? -1
7????????????? 1????????????? -1
8????????????? -1??????????? -1
9????????????? -1??????????? -1
10?????????? -1??????????? -1
", header=TRUE)

idx<- c(0,cumsum(abs(diff(dat1$Cola))))-as.integer(dat1$Cola!=dat1$Colb)
?split(dat1,idx)

A.K.

----- Original Message -----
From: Ian Arvin <ian at innovativequant.com>
To: r-help at r-project.org
Cc: 
Sent: Thursday, October 4, 2012 10:20 AM
Subject: [R] Subsetting a group of data

Hi,


I am making my way down the learning curve of R, and find it a great
language with so many helpful users!

Below is an example of what I'm trying to do, but can't quite figure out the
right path to go down.



Here's what I have:



Main is a time series of data with columns Cola and Colb

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

2? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

3? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

4? ? ? ? ? ? ? -1? ? ? ? ? ? 1

5? ? ? ? ? ? ? -1? ? ? ? ? ? -1

6? ? ? ? ? ? ? -1? ? ? ? ? ? -1

7? ? ? ? ? ? ? 1? ? ? ? ? ? ? -1

8? ? ? ? ? ? ? -1? ? ? ? ? ? -1

9? ? ? ? ? ? ? -1? ? ? ? ? ? -1

10? ? ? ? ?  -1? ? ? ? ? ? -1



What I would like is to subset the data into groups -? rows 1-3 into one
group (Cola and Colb both =1), then row 4 by itself, then rows 5-6, then row
7, then rows 8-10.

Group 1

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

2? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

3? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1



Group 2

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? -1? ? ? ? ? ? 1



Group 3

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? -1? ? ? ? ? ? -1

2? ? ? ? ? ? ? -1? ? ? ? ? ? -1



Thank you for your help!



Ian






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arun
# 
HI,
Another way to get the result:
dat1 <- read.table(text="
Cola?????? Colb
1????????????? 1????????????? 1
2????????????? 1????????????? 1
3????????????? 1????????????? 1
4????????????? -1??????????? 1
5????????????? -1??????????? -1
6????????????? -1??????????? -1
7????????????? 1????????????? -1
8????????????? -1??????????? -1
9????????????? -1??????????? -1
10?????????? -1??????????? -1
", header=TRUE)
list1<-split(dat1,within(dat1,{new1<-as.numeric(unlist(strsplit(gsub("AAA(\\d)AA(\\d).*","111\\133\\2555",gsub("(.*)B(.*)B(.*)","\\12\\24\\3",paste(ifelse(dat1$Cola==dat1$Colb,"A","B"),collapse=""))),"")))})[,3])
list1
#$`1`
?# Cola Colb
#1??? 1??? 1
#2??? 1??? 1
#3??? 1??? 1

#$`2`
?# Cola Colb
#4?? -1??? 1

#$`3`
?# Cola Colb
#5?? -1?? -1
#6?? -1?? -1

#$`4`
?# Cola Colb
#7??? 1?? -1

#$`5`
?#? Cola Colb
#8??? -1?? -1
#9??? -1?? -1
#10?? -1?? -1


A.K.

----- Original Message -----
From: Ian Arvin <ian at innovativequant.com>
To: r-help at r-project.org
Cc: 
Sent: Thursday, October 4, 2012 10:20 AM
Subject: [R] Subsetting a group of data

Hi,


I am making my way down the learning curve of R, and find it a great
language with so many helpful users!

Below is an example of what I'm trying to do, but can't quite figure out the
right path to go down.



Here's what I have:



Main is a time series of data with columns Cola and Colb

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

2? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

3? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

4? ? ? ? ? ? ? -1? ? ? ? ? ? 1

5? ? ? ? ? ? ? -1? ? ? ? ? ? -1

6? ? ? ? ? ? ? -1? ? ? ? ? ? -1

7? ? ? ? ? ? ? 1? ? ? ? ? ? ? -1

8? ? ? ? ? ? ? -1? ? ? ? ? ? -1

9? ? ? ? ? ? ? -1? ? ? ? ? ? -1

10? ? ? ? ?  -1? ? ? ? ? ? -1



What I would like is to subset the data into groups -? rows 1-3 into one
group (Cola and Colb both =1), then row 4 by itself, then rows 5-6, then row
7, then rows 8-10.

Group 1

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

2? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1

3? ? ? ? ? ? ? 1? ? ? ? ? ? ? 1



Group 2

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? -1? ? ? ? ? ? 1



Group 3

? ? ? ? ? ? ? ? Cola? ? ?  Colb

1? ? ? ? ? ? ? -1? ? ? ? ? ? -1

2? ? ? ? ? ? ? -1? ? ? ? ? ? -1



Thank you for your help!



Ian






??? [[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.