How can I change XTS to data.frame and keep Index?

Question

I have an XTS timeseries in R of the following format and am trying to do some processing, subsetting and re-arranging before exporting as a CSV for work in another program.

Answer 1

This is a bit of a sidebar, but the fortify(...) function in package ggplot2 will convert a variety of objects to data frames suitable for use in ggplot(...), including xts objects.

library(xts)
set.seed(1)    # for reproducible example
master_1 <- xts(rnorm(10,mean=2,sd=0.1),as.POSIXct("2010-03-03")+30*(0:9))

library(ggplot2)
df <- fortify(master_1)
head(df)
#                  Index master_1
# 1  2010-03-03 00:00:00 1.937355
# 2  2010-03-03 00:00:30 2.018364
# 3  2010-03-03 00:01:00 1.916437
# 4  2010-03-03 00:01:30 2.159528
# 5  2010-03-03 00:02:00 2.032951
# 6  2010-03-03 00:02:30 1.917953

So if you're already using gggplot this is an easy way to do it. Note that the index goes into a column named Index (capital "I").