Hi Camilo,
You can either use Henrik's or mine to find it,
?unlist(apply(dat1[,-(1:2)],1,function(x) tail(x[!is.na(x)],1)))
?x3? x2? x1
0.6 0.3 0.1
#or you can use my functiton
dat3<-data.frame(NewColumn=c(unlist(lapply(dat2,function(x) tail(x[!is.na(x)],1))),NA))
?dat4<-data.frame(dat1,dat3)
?rownames(dat4)<-1:nrow(dat4)
?dat4
#? Lat Lon? x1? x2? x3 NewColumn
#1?? 1? 12 0.4 0.5 0.6?????? 0.6
#2?? 1? 12 0.2 0.3? NA?????? 0.3
#3?? 1? 11 0.1? NA? NA?????? 0.1
#4?? 1? 10? NA? NA? NA??????? NA
A.K.
----- Original Message -----
From: Camilo Mora <cmora at dal.ca>
To: arun <smartpink111 at yahoo.com>
Cc: Henrik Singmann <henrik.singmann at psychologie.uni-freiburg.de>; R help <r-help at r-project.org>
Sent: Tuesday, July 24, 2012 10:56 PM
Subject: Re: First value in a row
Hi Henrik and Arun,
I now understand the script you provided. Very smart solution I think. I wonder, however, if there is an alternative way as to count the last number in a row?.
For instance, considering the following dataframe
dat1<-read.table(text="
Lat? Lon? x1? x2? x3
01? ? 12? .4? .5? .6
01? ? 12? .2? .3? NA
01? ? 11? .1? NA? NA
01? ? 10? NA? NA? NA
",sep="",header=TRUE)
the last value (from left to right) should be:
.6
.3
.1
NA
NAs are always consecutive once they appear.
Thanks again,
Camilo
Camilo Mora, Ph.D.
Department of Geography, University of Hawaii
Currently available in Colombia
Phone:?? Country code: 57
? ? ? ?? Provider code: 313
? ? ? ?? Phone 776 2282
? ? ? ?? From the USA or Canada you have to dial 011 57 313 776 2282
http://www.soc.hawaii.edu/mora/
Quoting arun <smartpink111 at yahoo.com>:
Hi Henrik,
Thanks for testing it to a different dataset.? I didn't test it at that time to multiple conditions.? Probably, apply is a better method.
Anyway, you can still get the same result by doing this:
dat1<-read.table(text="
Lat? Lon? x1? x2? x3
01? ? 10? NA? NA? .1
01? ? 11? .4? NA? .3
01? ? 12? NA? .5? .6
",sep="",header=TRUE)
dat2<-data.frame(t(dat1[,3:5]))
dat3<-data.frame(dat1,NewColumn=unlist(lapply(dat2,function(x) x[!is.na(x)][1])))
?row.names(dat3)<-1:nrow(dat3)
?dat3
#? Lat Lon? x1? x2? x3 NewColumn
#1?? 1? 10? NA? NA 0.1?????? 0.1
#2?? 1? 11 0.4? NA 0.3?????? 0.4
#3?? 1? 12? NA 0.5 0.6?????? 0.5
#Now, to a slightly different dataset
dat1<-read.table(text="
Lat? Lon? x1? x2? x3
01? ? 10? NA? NA? NA
01? ? 11? NA? NA? .3
01? ? 12? NA? .6?? NA
",sep="",header=TRUE)
?dat2<-data.frame(t(dat1[,3:5]))
?dat3<-data.frame(dat1,NewColumn=unlist(lapply(dat2,function(x) x[!is.na(x)][1])))
? row.names(dat3)<-1:nrow(dat3)
? dat3
? #Lat Lon x1? x2? x3 NewColumn
#1?? 1? 10 NA? NA? NA??????? NA
#2?? 1? 11 NA? NA 0.3?????? 0.3
#3?? 1? 12 NA 0.6? NA?????? 0.6
I hope this works well.
A.K.
----- Original Message -----
From: Henrik Singmann <henrik.singmann at psychologie.uni-freiburg.de>
To: arun <smartpink111 at yahoo.com>
Cc: Camilo Mora <cmora at dal.ca>; R help <r-help at r-project.org>
Sent: Tuesday, July 24, 2012 10:18 AM
Subject: Re: First value in a row
Hi,
As Arun's idea was also my first idea let me pinpoint the problem of this solution.
It only works if the data in question (i.e., columns x1 to x3) follow the pattern of the example data insofar that the NAs form a triangle like structure. This is so because it loops over columns instead of rows and takes advantage of the triangle NA structure.
For example, slightly changing the data leads to a result that does not follow the description of Camilo seem to want:
dat1<-read.table(text="
Lat? Lon? x1? x2? x3
01? ? 10? NA? NA? .1
01? ? 11? .4? NA? .3
01? ? 12? NA? .5? .6
",sep="",header=TRUE)
# correct answer from description would be .1, .4, .5
# arun's solution:
data.frame(dat1,NewColumn=rev(unlist(lapply(dat1[,3:5],function(x) x[!is.na(x)][1]))))
#? x3? x2? x1
# 0.1 0.5 0.4
# my solution:
apply(dat1[,-(1:2)], 1, function(x) x[!is.na(x)][1])
# [1] 0.1 0.4 0.5
So the question is, what you want and how the data looks.
Cheers,
Henrik
Am 24.07.2012 14:27, schrieb arun:
Hi,
Try this:
dat1<-read.table(text="
Lat? Lon? x1? x2? x3
01? ? 10? NA? NA? .1
01? ? 11? NA? .2? .3
01? ? 12? .4? .5? .6
",sep="",header=TRUE)
dat2<-dat1[,3:5]
?? dat3<-data.frame(dat1,NewColumn=rev(unlist(lapply(dat2,function(x) x[!is.na(x)][1]))))
row.names(dat3)<-1:nrow(dat3)
?? dat3
? ? Lat Lon? x1? x2? x3 NewColumn
1?? 1? 10? NA? NA 0.1? ? ?? 0.1
2?? 1? 11? NA 0.2 0.3? ? ?? 0.2
3?? 1? 12 0.4 0.5 0.6? ? ?? 0.4
A.K.
----- Original Message -----
From: Camilo Mora <cmora at dal.ca>
To: r-help at r-project.org
Cc:
Sent: Tuesday, July 24, 2012 2:48 AM
Subject: [R] First value in a row
Hi.
This is likely a trivial problem but have not found a solution. Imagine the following dataframe:
Lat?? Lon? x1?? x2? x3
01? ? 10?? NA?? NA? .1
01? ? 11?? NA?? .2? .3
01? ? 12?? .4?? .5? .6
I want to generate another column that consist of the first value in each row from columns x1 to x3. That is
NewColumn
.1
.2
.4
Any input greatly appreciated,
Thanks,
Camilo
Camilo Mora, Ph.D.
Department of Geography, University of Hawaii