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

[arun]

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



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