R help - Apr 2013 - Editing data sheet issue with write.table append

I'm running R 2.15.2 on Max OS X 10.6.8


If I write a simple file

Data1<-1
DF<-data.frame(Data1)
colnames(DF)<-"Col1"

and write to a csv file

write.table(DF,file="Data.csv",sep=",",row.names=FALSE,col.names=TRUE)

I can then append to it no problem

Data2<-2
Data3<-4


DF2<-data.frame(Data2)
DF3<-data.frame(Data3)

write.table(DF2,file="Data.csv",sep=",",row.names=FALSE,col.names=FALSE,append=TRUE)
write.table(DF3,file="Data.csv",sep=",",row.names=FALSE,col.names=FALSE,append=TRUE)


All good so far.

But the problem arises if I then need to edit the data sheet and continue
to append using the above code. If I open up the data sheet in excel and
delete a line, the next time I try and append the data as above the first
new line of data starts at the end of the last row of data (though all
subsequent new lines are appended properly).

I'm sure when I manually delete the line in excel I am removing the
invisible carriage return character, causing the first line of new data to
be added onto where the carriage return used to be.

Is there a way to specify in append=TRUE to always start with a new line of
data in the spreadsheet? Failing that, is there a work around to avoid this
problem?

	[[alternative HTML version deleted]]

a) Your terminology "data sheet" is foreign to R (and this mailing
list). It implies a computing model that R does not use.

b) You appear to be complaining about the behavior of software other than R on
the R-help mailing list, which is pointless.

c) I think the chances of adding code to base R to fix the broken behavior of
another software package is highly unlikely, particularly when from your
description you might or might not end up with the missing newline depending on
whether you choose to modify any particular file outside R. Putting in a newline
every time would make R just as broken as Excel.

4) You can put in newlines before or after your write.table call using the ?cat
function. Read the data input and output manual for details... but beware that
write.table is a high-level function that intentionally tries to generate a
coherent representation of the data table as a single block of text. If you need
to tweak within that text then you may need to make your own special output
function.
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Sent from my phone. Please excuse my brevity.

Vinny Moriarty <vwmoriarty at gmail.com> wrote:
>I'm running R 2.15.2 on Max OS X 10.6.8
>
>
>If I write a simple file
>
>Data1<-1
>DF<-data.frame(Data1)
>colnames(DF)<-"Col1"
>
>and write to a csv file
>
>write.table(DF,file="Data.csv",sep=",",row.names=FALSE,col.names=TRUE)
>
>I can then append to it no problem
>
>Data2<-2
>Data3<-4
>
>
>DF2<-data.frame(Data2)
>DF3<-data.frame(Data3)
>
>write.table(DF2,file="Data.csv",sep=",",row.names=FALSE,col.names=FALSE,append=TRUE)
>write.table(DF3,file="Data.csv",sep=",",row.names=FALSE,col.names=FALSE,append=TRUE)
>
>
>All good so far.
>
>But the problem arises if I then need to edit the data sheet and
>continue
>to append using the above code. If I open up the data sheet in excel
>and
>delete a line, the next time I try and append the data as above the
>first
>new line of data starts at the end of the last row of data (though all
>subsequent new lines are appended properly).
>
>I'm sure when I manually delete the line in excel I am removing the
>invisible carriage return character, causing the first line of new data
>to
>be added onto where the carriage return used to be.
>
>Is there a way to specify in append=TRUE to always start with a new
>line of
>data in the spreadsheet? Failing that, is there a work around to avoid
>this
>problem?
>
>	[[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.

On Apr 20, 2013, at 1:29 AM, Vinny Moriarty wrote:
> I'm running R 2.15.2 on Max OS X 10.6.8
> 
> 
> If I write a simple file
> 
> Data1<-1
> DF<-data.frame(Data1)
> colnames(DF)<-"Col1"
> 
> and write to a csv file
> 
>
write.table(DF,file="Data.csv",sep=",",row.names=FALSE,col.names=TRUE)
> 
> I can then append to it no problem
> 
> Data2<-2
> Data3<-4
> 
> 
> DF2<-data.frame(Data2)
> DF3<-data.frame(Data3)
> 
>
write.table(DF2,file="Data.csv",sep=",",row.names=FALSE,col.names=FALSE,append=TRUE)
>
write.table(DF3,file="Data.csv",sep=",",row.names=FALSE,col.names=FALSE,append=TRUE)
> 
> 
> All good so far.
> 
> But the problem arises if I then need to edit the data sheet and continue
> to append using the above code. If I open up the data sheet in excel and
> delete a line, the next time I try and append the data as above the first
> new line of data starts at the end of the last row of data (though all
> subsequent new lines are appended properly).
> 
> I'm sure when I manually delete the line in excel I am removing the
> invisible carriage return character, causing the first line of new data to
> be added onto where the carriage return used to be.
> 
> Is there a way to specify in append=TRUE to always start with a new line of
> data in the spreadsheet?
No. 
> Failing that, is there a work around to avoid this
> problem?
You could always execute this before each append effort to restore the
Excel-induced missing end of line character:

cat"\n", file="Data.csv", append=TRUE)


-- 

David Winsemius
Alameda, CA, USA