Dear R People:
Suppose I have the following data frame:
x1 x2 x3
1 -0.1582116 0.06635783 1.765448
2 -1.1407422 0.47235664 0.615931
3 0.8702362 2.32301341 2.653805> str(xx)
'data.frame': 3 obs. of 3 variables:
$ x1: num -0.158 -1.141 0.87
$ x2: num 0.0664 0.4724 2.323
$ x3: num 1.765 0.616 2.654
I can exclude the second column nicely via:> xx[,-2]
x1 x3
1 -0.1582116 1.765448
2 -1.1407422 0.615931
3 0.8702362 2.653805
Now suppose I wanted to exclude the column called "x2". If I
try:> xx[,-"x2"]
Error in -"x2" : invalid argument to unary
operator>
things don't work. Is there a simple way to do this by name rather
than number, please?
Thanks,
Erin
--
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: erinm.hodgess at gmail.com
Tena koe Erin xx[, names(xx)!='x2'] HTH .... Peter Alspach> -----Original Message----- > From: r-help-bounces at r-project.org > [mailto:r-help-bounces at r-project.org] On Behalf Of Erin Hodgess > Sent: Wednesday, 15 April 2009 5:39 p.m. > To: R help > Subject: [R] excluding a column from a data frame > > Dear R People: > > Suppose I have the following data frame: > > x1 x2 x3 > 1 -0.1582116 0.06635783 1.765448 > 2 -1.1407422 0.47235664 0.615931 > 3 0.8702362 2.32301341 2.653805 > > str(xx) > 'data.frame': 3 obs. of 3 variables: > $ x1: num -0.158 -1.141 0.87 > $ x2: num 0.0664 0.4724 2.323 > $ x3: num 1.765 0.616 2.654 > > I can exclude the second column nicely via: > > xx[,-2] > x1 x3 > 1 -0.1582116 1.765448 > 2 -1.1407422 0.615931 > 3 0.8702362 2.653805 > > Now suppose I wanted to exclude the column called "x2". If I try: > > xx[,-"x2"] > Error in -"x2" : invalid argument to unary operator > > > > things don't work. Is there a simple way to do this by name > rather than number, please? > > Thanks, > Erin > > > > -- > Erin Hodgess > Associate Professor > Department of Computer and Mathematical Sciences University > of Houston - Downtown > mailto: erinm.hodgess at gmail.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. >The contents of this e-mail are confidential and may be subject to legal privilege. If you are not the intended recipient you must not use, disseminate, distribute or reproduce all or any part of this e-mail or attachments. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail. Any opinion or views expressed in this e-mail are those of the individual sender and may not represent those of The New Zealand Institute for Plant and Food Research Limited.
On 4/15/2009 1:38 AM, Erin Hodgess wrote:> Dear R People: > > Suppose I have the following data frame: > > x1 x2 x3 > 1 -0.1582116 0.06635783 1.765448 > 2 -1.1407422 0.47235664 0.615931 > 3 0.8702362 2.32301341 2.653805 >> str(xx) > 'data.frame': 3 obs. of 3 variables: > $ x1: num -0.158 -1.141 0.87 > $ x2: num 0.0664 0.4724 2.323 > $ x3: num 1.765 0.616 2.654 > > I can exclude the second column nicely via: >> xx[,-2] > x1 x3 > 1 -0.1582116 1.765448 > 2 -1.1407422 0.615931 > 3 0.8702362 2.653805 > > Now suppose I wanted to exclude the column called "x2". If I try: >> xx[,-"x2"] > Error in -"x2" : invalid argument to unary operator > > things don't work. Is there a simple way to do this by name rather > than number, please?Another way to do it is with subset(): subset(xx, select = -x2)> Thanks, > Erin-- Chuck Cleland, Ph.D. NDRI, Inc. (www.ndri.org) 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 512-0171 (M, W, F) fax: (917) 438-0894
How about:
xx[,-match("x2",names(xx))]
or
xx[,names(xx) != "x2"]
etc.
Bert Gunter
Genentech Nonclinical Biostatistics
650-467-7374
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On
Behalf Of Erin Hodgess
Sent: Tuesday, April 14, 2009 10:39 PM
To: R help
Subject: [R] excluding a column from a data frame
Dear R People:
Suppose I have the following data frame:
x1 x2 x3
1 -0.1582116 0.06635783 1.765448
2 -1.1407422 0.47235664 0.615931
3 0.8702362 2.32301341 2.653805> str(xx)
'data.frame': 3 obs. of 3 variables:
$ x1: num -0.158 -1.141 0.87
$ x2: num 0.0664 0.4724 2.323
$ x3: num 1.765 0.616 2.654
I can exclude the second column nicely via:> xx[,-2]
x1 x3
1 -0.1582116 1.765448
2 -1.1407422 0.615931
3 0.8702362 2.653805
Now suppose I wanted to exclude the column called "x2". If I
try:> xx[,-"x2"]
Error in -"x2" : invalid argument to unary
operator>
things don't work. Is there a simple way to do this by name rather
than number, please?
Thanks,
Erin
--
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: erinm.hodgess at gmail.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.