[R] write.csv() : attempt to set 'append' ignored... Why?

[Marc Schwartz]

On Jul 15, 2010, at 9:41 AM, Cliff Clive wrote:

> 
> I'm running R 2.11.0 on a 32-bit Windows XP machine.  Whenever I try to write
> a csv file with 'append' set to TRUE, I get this message: attempt to set
> 'append' ignored.
> 
> Obviously, this is no good, since R is deleting my previously saved data
> files, rather than appending to them.  What can I do to fix this?


Read ?write.csv more carefully:

In the "CSV files" section:

These wrappers are deliberately inflexible: they are designed to ensure that the correct conventions are used to write a valid file. Attempts to change append, col.names, sep, dec or qmethod are ignored, with a warning.


If you want to use 'append', you will need to use write.table() and adjust the other arguments as you require.

HTH,

Marc Schwartz