[R] aggregate text column by a few rows

Hi, R function aggregate can only take summary stats functions, can I aggregate text columns? For example, for the dataframe below, a - rbind(data.frame(id=1, name='Tom', hobby='fishing'),data.frame(id=1, name='Tom', hobby='reading'),data.frame(id=2, name='Mary',

Re: [R] aggregate text column by a few rows

try this using sqldf: a id name hobby 1 1 Tom fishing 2 1 Tom reading 3 2 Mary reading 4 3 John boating 5 2 Mary running require(sqldf) sqldf('select name, group_concat(hobby) hobby from a group by id', method='raw') name hobby 1 Tom fishing,reading 2 Mary

Re: [R] aggregate text column by a few rows

Or: data.frame( hobs= tapply(a$hobby, list( a$name), c)) hobs Tom fishing, reading Mary reading, running John boating Note Jim's gives you the names as columns while this has them as rownames. Further differences : my version has the column as lists whereas Jim's

Re: [R] aggregate text column by a few rows

Try this: aggregate(hobby ~ id + name, a, FUN = toString) On Thu, Oct 7, 2010 at 12:52 PM, Tan, Richard r...@panagora.com wrote: Hi, R function aggregate can only take summary stats functions, can I aggregate text columns? For example, for the dataframe below, a -

Re: [R] aggregate text column by a few rows

Richard - Yes, you certainly can use aggregate to acheive what you want: aggregate(a$hobby,a['name'],paste,collapse=' ') name x 1 Tom fishing reading 2 Mary reading running 3 John boating - Phil Spector

Re: [R] aggregate text column by a few rows

Thank you! Richard -Original Message- From: jim holtman [mailto:jholt...@gmail.com] Sent: Thursday, October 07, 2010 12:08 PM To: Tan, Richard Cc: r-help@r-project.org Subject: Re: [R] aggregate text column by a few rows try this using sqldf: a id name hobby 1 1 Tom fishing 2