[R] data frame: adding columns from data and file title

[jim holtman]

Here is how to get the information from the file name that you want:

> # let's assume you have the filename
> fileName <- "G7_pig328_unit328_Site141_30MAR2012_RNo4_SitNo1.csv"
> # parse it for the group and bird names
> group <- sub("^G([0-9]+).*", "\\1", fileName)
> bird <- sub(".*pig([0-9]+).*", "\\1", fileName)
> group
[1] "7"
> bird
[1] "328"
>
>



On Wed, Nov 28, 2012 at 7:40 AM, arun <smartpink111 at yahoo.com> wrote:
> Hi,
> TRy this:
> dat1 <- read.table(text="
> Date_ Time_ Speed  Course  Type_  Distance
> 30/03/2012  11:15:05  108  121  -2 0
> 30/03/2012  11:15:06    0  79  0 0
> 30/03/2012  11:15:07    0  76  0 1
> 30/03/2012  11:15:08    0  86  0 2
> 30/03/2012  11:15:09    0  77  0 3
> ", header = TRUE, stringsAsFactors = FALSE)
> fileN <- "G7_pig328_unit328_Site141_30MAR2012_RNo4_SitNo1.csv"
> dat1$cDistance<-cumsum(dat1$Distance)
>
> dat1$Group<-as.numeric(unlist(strsplit(gsub("^\\D+(\\d+)\\D+(\\d+).*","\\1 \\2",fileN)," ")))[1]
>  dat1$BIRD<-as.numeric(unlist(strsplit(gsub("^\\D+(\\d+)\\D+(\\d+).*","\\1 \\2",fileN)," ")))[2]
> dat1
> A.K.
>
>
>
> ----- Original Message -----
> From: jgui001 <j.guilbert at auckland.ac.nz>
> To: r-help at r-project.org
> Cc:
> Sent: Wednesday, November 28, 2012 4:33 AM
> Subject: [R] data frame: adding columns from data and file title
>
> Data processing”
>
> I have a large number of csv files from animal tracks that look like this:
>
> Date_                                  Time_                              Speed
> Course                              Type_                              Distance
> 30/03/2012                          11:15:05                              108
> 121                                                        -2
> 0
> 30/03/2012                          11:15:06                              0
> 79                                                        0                              0
> 30/03/2012                              11:15:07                              0
> 76                                                        0                              1
> 30/03/2012                              11:15:08                              0
> 86                                                        0                              2
> 30/03/2012                              11:15:09                              0
> 77                                                        0                              3
>
> Each file has a name like this
> “G7_pig328_unit328_Site141_30MAR2012_RNo4_SitNo1.csv”
>
> To automate the processing I would like to
> 1. Add on various columns calculated from within the data frame e.g.
> cumulative distance traveled (cDistance) by Summing the distance column from
> [1 :n] for each row
> 2 Add columns derived from the file name so when I merge all the files
> together I know what observation corresponds to which group and bird etc.
> For example G7 stands for group 7, pig328 is pigeon328:
>
> The file look the same with but with these columns (plus others) added
>
> cDistance                              Group              BIRD
> 0                                                       7              328
> 0                                                      7              328
> 1                                                      7              328
> 3                                                      7              328
> 6                                                     7              328
>
> I was thinking a function like this for cDistance (if I can get it to work)
>
> cdistamce <-funtion(x){
>    i = 1
>    j=nrow(temp1.df)
>   while(i<=j,ifelse(i=1,"Distance[i]",Sum("Distance"))
>         i=i+1
> }
>
> But hit a brick wall and I have no idea about adding columns from the name.
> Am I on the right track with the first one and any ideas, coz I can't brain
> today I have the dumb!?
>
> Cheers
> Josh
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/data-frame-adding-columns-from-data-and-file-title-tp4651099.html
> Sent from the R help mailing list archive at Nabble.com.
>
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>
>
> ______________________________________________
> R-help at 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.



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.