This function provides a high level API for writing a data.frame
to an Excel 2007 worksheet. It calls several low level functions in the
process. Its goal is to provide the conveniency of
write.csv
by borrowing from its signature.
Internally, write.xlsx
uses a double loop in R over all the
elements of the data.frame
so performance for very large
data.frame
may be an issue. Please report if you experience slow
performance. Dates and POSIXct classes are formatted separately after
the insertion. This also adds to processing time.
If x
is not a data.frame
it will be converted to one.
Function write.xlsx2
uses addDataFrame
which speeds up the
execution compared to write.xlsx
by an order of magnitude for
large spreadsheets (with more than 100,000 cells).
The default formats for Date and DateTime columns can be changed via the
two package options xlsx.date.format
and
xlsx.datetime.format
. They need to be specified in Java date
format
http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html.
Writing of password protected workbooks is supported for
Excel 2007 OOXML format only. Note that in Linux, LibreOffice is not
able to read password protected spreadsheets.