Ted Zeng (曾振兴)
2010-Jan-31 19:25 UTC
[R] How to split data frame into groups by a list of factors?
Dear R users:
I am dealing a data frame x as followings:
Date trade_day IV.b IV.a
1 2003-03-02 19 0.1724818 0.1815687
2 2003-03-02 18 0.1733542 0.1763827
3 2003-03-02 19 0.1753308 0.1783653
4 2003-03-03 16 0.1751217 0.1781624
5 2003-03-03 16 0.1738580 0.1768961
6 2003-03-03 19 0.1733346 0.1763800
......
I want to split the data flame into groups according to the variable
"Date"
and "trade_day"
I tried: split(x,f=list(a=x$Date,b=x$trade_day)), but it doesn't work. How
can I solve this problem?
Thanks advance
Ted
--
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jim holtman
2010-Jan-31 20:19 UTC
[R] How to split data frame into groups by a list of factors?
This seems to work fine for me:> x <- read.table(textConnection(" Date trade_day IV.b IV.a+ 1 2003-03-02 19 0.1724818 0.1815687 + 2 2003-03-02 18 0.1733542 0.1763827 + 3 2003-03-02 19 0.1753308 0.1783653 + 4 2003-03-03 16 0.1751217 0.1781624 + 5 2003-03-03 16 0.1738580 0.1768961 + 6 2003-03-03 19 0.1733346 0.1763800"), header=TRUE)> closeAllConnections() > split(x, list(x$Date, x$trade_day), drop=TRUE)$`2003-03-03.16` Date trade_day IV.b IV.a 4 2003-03-03 16 0.1751217 0.1781624 5 2003-03-03 16 0.1738580 0.1768961 $`2003-03-02.18` Date trade_day IV.b IV.a 2 2003-03-02 18 0.1733542 0.1763827 $`2003-03-02.19` Date trade_day IV.b IV.a 1 2003-03-02 19 0.1724818 0.1815687 3 2003-03-02 19 0.1753308 0.1783653 $`2003-03-03.19` Date trade_day IV.b IV.a 6 2003-03-03 19 0.1733346 0.17638>On Sun, Jan 31, 2010 at 2:25 PM, Ted Zeng (???) <zengzhenxing at gmail.com> wrote:> > Dear R users: > > I am dealing a data frame x as followings: > > ? ? ? Date trade_day ? ? ?IV.b ? ? ?IV.a > 1 2003-03-02 ? ? ? ?19 0.1724818 0.1815687 > 2 2003-03-02 ? ? ? ?18 0.1733542 0.1763827 > 3 2003-03-02 ? ? ? ?19 0.1753308 0.1783653 > 4 2003-03-03 ? ? ? ?16 0.1751217 0.1781624 > 5 2003-03-03 ? ? ? ?16 0.1738580 0.1768961 > 6 2003-03-03 ? ? ? ?19 0.1733346 0.1763800 > ...... > > I want to split the data flame into groups according to the variable "Date" > and "trade_day" > I tried: split(x,f=list(a=x$Date,b=x$trade_day)), but it doesn't work. How > can I solve this problem? > > Thanks advance > > Ted > -- > View this message in context: http://n4.nabble.com/How-to-split-data-frame-into-groups-by-a-list-of-factors-tp1458171p1458171.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?