Re: [R] Adding header lines to a dataframe that is exported using write.csv

From: Henrik Bengtsson <>
Date: Mon 27 Feb 2006 - 22:03:00 EST

Just a tips: When you add headers to tabulate files like yours, it is convenient to start each header line with a '#' (like an R comment), because then read.table() will not complain about the header lines. It is easy to strip the '#' off the header lines, i.e. grep("^#", "", hlines) before further parsing.


On 2/25/06, Mark <> wrote:
> I would like to export a dataframe to a .csv using:
> >write.csv(dataframe,"dataframe.csv")
> but I need to add four "header" lines to the csv that are not part of
> the dataframe (which itself has a line of column headers).
> The difficulty (for me, at least!) lies in the requirement that
> certain elements of the header (X, Y and the number of "Q"s - please
> see example below) must be defined based on the number of rows and
> columns in the dataframe, which vary depending on the input file.
> Here's what the 3 .csv header lines should look like, followed by a
> number of dataframe rows (i.e., these lines are not R code, but are
> what R will produce).
> X, plots ,,,, #where X=number of rows in the dataframe
> Y, species,,,, #where Y=number of columns in the dataframe
> ,Q,Q,Q,Q,Q #where the number of Qs=the number of columns in the dataframe
> Those 3 .csv header lines would be followed by dataframe, which
> consists of one row containing column headers and X "data" rows:
> ,spec1,spec2,spec3,sp3c4,spec5 #these are the dataframe's column headers
> plot1,15.84,0,0,792,7 #this is an example "data" row
> In case the above is unclear, I have also attached a small .csv as an
> example of what the output should look like.
> Thank you. Mark
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Henrik Bengtsson
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Received on Mon Feb 27 22:21:51 2006

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