Re: [R] Extract values from vector and repeat by group
Brilliant - thanks for all the really useful suggestions, problem = solved.
Many thanks,
Ben Gillespie, Research Postgraduate
o---o
School of Geography, University of Leeds, Leeds, LS2 9JT
o---o
Tel: +44(0)113 34 33345
Mob: +44(0)770 868 7641
o---o
http://www.geog.leeds.ac.uk/
o-o
@RiversBenG
o--o
From: arun [smartpink...@yahoo.com]
Sent: 17 November 2013 16:48
To: R help
Cc: Berend Hasselman; Benjamin Gillespie
Subject: Re: [R] Extract values from vector and repeat by group
Hi,
?merge() sometimes change the order.
For example:
df1 - df[-12,]
df2 - df1
merge(df1, df1[df1$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
In that case,
df1$ord1 - with(df1,order(group,time))
res - merge(df1, df1[df1$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
res[order(res$ord1),-4]
#or just
library(plyr)
join(df2,df2[df2$time==4,c(group,var)],by=group,type=inner)
#or you may use:
indx - with(df1,ave(time==4,group,FUN=any))
ddply(df1[indx,],.(group),mutate,new=var[time==4])
A.K.
On Sunday, November 17, 2013 10:22 AM, Berend Hasselman b...@xs4all.nl wrote:
On 17-11-2013, at 15:47, Benjamin Gillespie gy...@leeds.ac.uk wrote:
Hi all,
I hope you can help.
I have a data frame 'df':
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
I would like to extract the value from 'var' for each 'group' at 'time'=4 and
repeat these extracted values in a new vector ('new') n times where n is the
number of rows for each group. I did this by hand as below, but there must be
a quicker way:
subset=subset(df,df$time==4)
subset
groupvar time
4 1 0.25312704
12 2 -0.36001284
22 3 0.41947304
df$new=c(rep(0.2531270,8),rep(-0.3600128,10),rep(0.4194730,11))
Any questions please ask,
A very similar question was recently asked on Stackoverflow:
http://stackoverflow.com/questions/19971763/r-programming-normalizing-a-column-of-data-by-another-entry-in-2-other-columns
From the answer given there you could try this
set.seed(11) # to make it reproducible
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
#df
#df[df$time==4, c(group, var)]
# merge into original data.frame
df - merge(df, df[df$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
df
Berend
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Extract values from vector and repeat by group
Hi
probably not most elegant and also not general but
rep(df$var[df$time==4],rle(df$group)$lengths)
or
rep(df$var[df$time==4], sapply(split(df$var,df$group), length))
shall give you desired vector.
Regards
Petr
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-bounces@r-
project.org] On Behalf Of Benjamin Gillespie
Sent: Sunday, November 17, 2013 3:47 PM
To: r-help@r-project.org
Subject: [R] Extract values from vector and repeat by group
Hi all,
I hope you can help.
I have a data frame 'df':
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
I would like to extract the value from 'var' for each 'group' at
'time'=4 and repeat these extracted values in a new vector ('new') n
times where n is the number of rows for each group. I did this by hand
as below, but there must be a quicker way:
subset=subset(df,df$time==4)
subset
groupvar time
4 1 0.25312704
12 2 -0.36001284
22 3 0.41947304
df$new=c(rep(0.2531270,8),rep(-0.3600128,10),rep(0.4194730,11))
Any questions please ask,
Many thanks in advance,
Ben Gillespie, Research Postgraduate
o---o
School of Geography, University of Leeds, Leeds, LS2 9JT o-
--o
Tel: +44(0)113 34 33345
Mob: +44(0)770 868 7641
o---o
http://www.geog.leeds.ac.uk/
o-o
@RiversBenG
o--o
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-
guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Extract values from vector and repeat by group
Hi,
I would also add an index to make it work for groups that doesn't have time=4.
df1 - df[-12,]
fun1 - function(dat,n) {
indx - with(dat,tapply(time==n,group,FUN=any))
indx2 - with(dat,ave(time==n,group,FUN=any))
dat[indx2,new] - rep(dat$var[dat$time==n],rle(dat$group)$lengths[indx])
dat[!is.na(dat$new),]
}
fun1(df,4)
fun1(df1,4)
A.K.
On Monday, November 18, 2013 9:18 AM, PIKAL Petr petr.pi...@precheza.cz wrote:
Hi
probably not most elegant and also not general but
rep(df$var[df$time==4],rle(df$group)$lengths)
or
rep(df$var[df$time==4], sapply(split(df$var,df$group), length))
shall give you desired vector.
Regards
Petr
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-bounces@r-
project.org] On Behalf Of Benjamin Gillespie
Sent: Sunday, November 17, 2013 3:47 PM
To: r-help@r-project.org
Subject: [R] Extract values from vector and repeat by group
Hi all,
I hope you can help.
I have a data frame 'df':
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
I would like to extract the value from 'var' for each 'group' at
'time'=4 and repeat these extracted values in a new vector ('new') n
times where n is the number of rows for each group. I did this by hand
as below, but there must be a quicker way:
subset=subset(df,df$time==4)
subset
group var time
4 1 0.2531270 4
12 2 -0.3600128 4
22 3 0.4194730 4
df$new=c(rep(0.2531270,8),rep(-0.3600128,10),rep(0.4194730,11))
Any questions please ask,
Many thanks in advance,
Ben Gillespie, Research Postgraduate
o---o
School of Geography, University of Leeds, Leeds, LS2 9JT o-
--o
Tel: +44(0)113 34 33345
Mob: +44(0)770 868 7641
o---o
http://www.geog.leeds.ac.uk/
o-o
@RiversBenG
o--o
__
R-help@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.
__
R-help@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.
__
R-help@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.
[R] Extract values from vector and repeat by group
Hi all,
I hope you can help.
I have a data frame 'df':
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
I would like to extract the value from 'var' for each 'group' at 'time'=4 and
repeat these extracted values in a new vector ('new') n times where n is the
number of rows for each group. I did this by hand as below, but there must be a
quicker way:
subset=subset(df,df$time==4)
subset
groupvar time
4 1 0.25312704
12 2 -0.36001284
22 3 0.41947304
df$new=c(rep(0.2531270,8),rep(-0.3600128,10),rep(0.4194730,11))
Any questions please ask,
Many thanks in advance,
Ben Gillespie, Research Postgraduate
o---o
School of Geography, University of Leeds, Leeds, LS2 9JT
o---o
Tel: +44(0)113 34 33345
Mob: +44(0)770 868 7641
o---o
http://www.geog.leeds.ac.uk/
o-o
@RiversBenG
o--o
__
R-help@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.
Re: [R] Extract values from vector and repeat by group
On 17-11-2013, at 15:47, Benjamin Gillespie gy...@leeds.ac.uk wrote:
Hi all,
I hope you can help.
I have a data frame 'df':
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
I would like to extract the value from 'var' for each 'group' at 'time'=4 and
repeat these extracted values in a new vector ('new') n times where n is the
number of rows for each group. I did this by hand as below, but there must be
a quicker way:
subset=subset(df,df$time==4)
subset
groupvar time
4 1 0.25312704
12 2 -0.36001284
22 3 0.41947304
df$new=c(rep(0.2531270,8),rep(-0.3600128,10),rep(0.4194730,11))
Any questions please ask,
A very similar question was recently asked on Stackoverflow:
http://stackoverflow.com/questions/19971763/r-programming-normalizing-a-column-of-data-by-another-entry-in-2-other-columns
From the answer given there you could try this
set.seed(11) # to make it reproducible
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
#df
#df[df$time==4, c(group, var)]
# merge into original data.frame
df - merge(df, df[df$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
df
Berend
__
R-help@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.
Re: [R] Extract values from vector and repeat by group
Hi,
?merge() sometimes change the order.
For example:
df1 - df[-12,]
df2 - df1
merge(df1, df1[df1$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
In that case,
df1$ord1 - with(df1,order(group,time))
res - merge(df1, df1[df1$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
res[order(res$ord1),-4]
#or just
library(plyr)
join(df2,df2[df2$time==4,c(group,var)],by=group,type=inner)
#or you may use:
indx - with(df1,ave(time==4,group,FUN=any))
ddply(df1[indx,],.(group),mutate,new=var[time==4])
A.K.
On Sunday, November 17, 2013 10:22 AM, Berend Hasselman b...@xs4all.nl wrote:
On 17-11-2013, at 15:47, Benjamin Gillespie gy...@leeds.ac.uk wrote:
Hi all,
I hope you can help.
I have a data frame 'df':
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
I would like to extract the value from 'var' for each 'group' at 'time'=4 and
repeat these extracted values in a new vector ('new') n times where n is the
number of rows for each group. I did this by hand as below, but there must be
a quicker way:
subset=subset(df,df$time==4)
subset
group var time
4 1 0.2531270 4
12 2 -0.3600128 4
22 3 0.4194730 4
df$new=c(rep(0.2531270,8),rep(-0.3600128,10),rep(0.4194730,11))
Any questions please ask,
A very similar question was recently asked on Stackoverflow:
http://stackoverflow.com/questions/19971763/r-programming-normalizing-a-column-of-data-by-another-entry-in-2-other-columns
From the answer given there you could try this
set.seed(11) # to make it reproducible
group=c(rep(1,8),rep(2,10),rep(3,11))
var=rnorm(29)
time=c(seq(1,8),seq(1,10),seq(1,11))
df=data.frame(group,var,time)
#df
#df[df$time==4, c(group, var)]
# merge into original data.frame
df - merge(df, df[df$time == 4, c(group, var)], by.x = group, by.y =
group, suffixes = c(, GroupSK0))
df
Berend
__
R-help@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.
__
R-help@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.
