[R] Questions remaining: define any character as na.string RE: merging data list in to single data frame

[David Winsemius]

On Apr 4, 2011, at 12:37 PM, Umesh Rosyara wrote:

> Dear Uwe and R community members
>
> Thank you Uwe for the help.
>
> I have still a question remaining, I am trying to find answer from  
> long
> time.
>
> While exporting my data, I have some characters mixed into it. I  
> want to
> define any characters as na.string? Is it possible to do so?

Option 1: do it in an editor that is regex aware.
Option 2: input the file with readLines, use gsub to remove the  
unwanted characters, read.table(textConnection(obj))  on the resulting  
object. [There are many worked examples in the archives. Search on  
"read.table(textConnection("  .]

-- 
David.


>
> Thanks;
>
> Umesh
>
>
>
> -----Original Message-----
> From: Uwe Ligges [mailto:ligges at statistik.tu-dortmund.de]
> Sent: Monday, April 04, 2011 12:22 PM
> To: Umesh Rosyara
> Cc: r-help at r-project.org; rosyaraur at gmail.com
> Subject: Re: [R] merging data list in to single data frame
>
>
>
> On 04.04.2011 16:41, Umesh Rosyara wrote:
>> Dear R community members
>>
>>
>>
>> I did find a good way to merge my 200 text data files in to a  
>> single data
>> file with one column added will show indicator for that file.
>>
>>
>>
>> filelist = list.files(pattern = "K*cd.txt")
>
>
> I doubt you meant "K*cd.txt" but "^K[[:digit:]]*cd\\.txt$".
>
>
>
> # the file names are K1cd.txt
>> .................to K200cd.txt
>>
>> data_list<-lapply(filelist, read.table, header=T, comment=";",  
>> fill=T)
>
>
> Replace by:
>
> data_list <- lapply(filelist, function(x)
>    cbind(Filename = x, read.table(x, header=T, comment=";",  
> fill=TRUE))
>
>
> And then:
>
> result <- do.call("rbind", data_list)
>
> Uwe Ligges
>
>
>>
>>
>>
>> This will create list, but this is not what I want.
>>
>>
>>
>> I want a single dataframe (all separate dataframes have same variable
>> headings) with additional row for example
>>
>>
>>
>> ; just for example, two small datasets are created by my component
> datasets
>> are huge, need automation
>>
>> ;read from file K1cd.txt
>>
>> var1  var2  var3    var4
>>
>> 1           6         0.3         8
>>
>> 3          4         0.4         9
>>
>> 2          3         0.4         6
>>
>> 1           0.4    0.9          3
>>
>>
>>
>> ;read from file K2cd.txt
>>
>> var1  var2  var3    var4
>>
>> 1           16         0.6        7
>>
>> 3          14         0.4         6
>>
>> 2         1 3         0.4         5
>>
>> 1          0.6    0.9          2
>>
>>
>>
>> the output dataframe should look like
>>
>>
>>
>> Fileno  var1  var2  var3    var4
>>
>> 1              1           6         0.3        8
>>
>> 1              3          4         0.4         9
>>
>> 1              2          3         0.4         6
>>
>> 1              1           0.4      0.9        3
>>
>> 2              1           16       0.6        7
>>
>> 2              3          14         0.4        6
>>
>> 2              2         1 3         0.4        5
>>
>> 2              1          0.6         0.9       2
>>
>>
>>
>> Please note that new file no column is added
>>
>>
>>
>> Thank you for the help.
>>
>>
>>
>> Umesh R
>>
>>
>>
>>
>> 	[[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.
>
> ______________________________________________
> 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.

David Winsemius, MD
West Hartford, CT