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Questions for manipulating datasets in R e.g. sorting and matching

3 messages · Stefanie von Felten, IPW&IfU, Dimitris Rizopoulos, Christian Montel

Stefanie von Felten, IPW&IfU
# 
Hello everyone,

I want to sort a dataset in R, using multiple columns as sorting 
criteria. I know I can sort a dataset "Data" with 14 columns using one 
column (the fifth), by typing:

DataSort<-Data[order(Data[,5]),1:14]

But how can the dataset be sorted by column 5, then by 6, then by 8?

Another question is, how two datasets can be matched by a column present 
in both of them?

Steffi
Dimitris Rizopoulos
# 
regarding your 1st question you can still use order(), i.e., 
order(Data[,5], Data[,6], Data[,8]); regarding you 2nd question look 
at ?merge.

I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://www.med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "Stefanie von Felten, IPW&IfU" <sfelten at uwinst.unizh.ch>
To: <r-help at stat.math.ethz.ch>
Sent: Thursday, February 23, 2006 10:06 AM
Subject: [R] Questions for manipulating datasets in R e.g. sorting 
andmatching


Hello everyone,

I want to sort a dataset in R, using multiple columns as sorting
criteria. I know I can sort a dataset "Data" with 14 columns using one
column (the fifth), by typing:

DataSort<-Data[order(Data[,5]),1:14]

But how can the dataset be sorted by column 5, then by 6, then by 8?

Another question is, how two datasets can be matched by a column 
present
in both of them?

Steffi
Christian Montel
# 
hi steffi,

try
DataSort<-Data[order(Data[,5],Data[,6],Data[,8]),1:14]

and for further details ?order. For matching try ?merge.

Best Regards,

Christian

Stefanie von Felten, IPW&IfU schrieb: