问题
Possible Duplicate:
How to create a variable of rownames?
Please run it in R:
require(quantmod)
setSymbolLookup(SDB=list(name="000001.sz",src="yahoo"))
getSymbols("SDB",from="2010-01-01",to="2010-02-01")
sdb=as.data.frame(weeklyReturn(SDB))
sdb
What I get is:
weekly.returns
2010-01-08 -0.07830343
2010-01-15 -0.05176991
2010-01-22 0.07699487
2010-01-29 -0.05979203
2010-02-01 -0.02119816
What I want to get is:
date weekly.returns
1 2010-01-08 -0.07830343
2 2010-01-15 -0.05176991
3 2010-01-22 0.07699487
4 2010-01-29 -0.05979203
5 2010-02-01 -0.02119816
How can I do this?
Note that this is an XTS object, not a basic data.frame. After the conversion, I want the original rownames to appear as a new variable in the resulting data.frame.
回答1:
Ok. So, it's not exactly the same as your earlier question since this is an XTS object. Still, very easy to take care of:
data.frame(date = index(weeklyReturn(SDB)),
weeklyReturn(SDB), row.names=NULL)
# date weekly.returns
# 1 2010-01-04 -0.03303426
# 2 2010-01-11 -0.04681569
# 3 2010-01-18 -0.05000000
# 4 2010-01-25 0.03353517
# 5 2010-02-01 -0.04281208
For help on what is being done here, view use ?indexClass to read the documentation for index in the XTS package.
来源：https://stackoverflow.com/questions/11429889/converting-an-xts-object-to-a-data-frame