[R] reshaping a data frame

[Abhishek Pratap]

Thanks everyone for your quick reply. I think my contrived example hid
the complexity I wanted to show by using only one variable.

@Arun: I think your example is exactly what I was looking for. Very
cool trick with 'ave' and 'seq_along'...just dint occur to me.

Best,
-Abh

>
> On Mon, Jun 10, 2013 at 7:13 AM, arun <smartpink111 at yahoo.com> wrote:
>> Hi,If your dataset is similar to the one below:
>> set.seed(24)
>> temp1_df<- data.frame(names=rep(c('foo','foo1'),each=6),variable=rep(c('w','x'),times=6),value=sample(25:40,12,replace=TRUE),stringsAsFactors=FALSE)
>>
>> library(reshape2)
>>  res<-dcast(within(temp1_df,{Seq1<-ave(value,names,variable,FUN=seq_along)}),names+Seq1~variable,value.var="value")[,-2]
>> res
>> #  names  w  x
>> #1   foo 29 28
>> #2   foo 36 33
>> #3   foo 35 39
>> #4  foo1 29 37
>> #5  foo1 37 29
>> #6  foo1 34 30
>> A.K.
>>
>>
>> ----- Original Message -----
>> From: Abhishek Pratap <abhishek.vit at gmail.com>
>> To: "r-help at r-project.org" <r-help at r-project.org>
>> Cc:
>> Sent: Monday, June 10, 2013 2:15 AM
>> Subject: [R] reshaping a data frame
>>
>> Hi Guys
>>
>> I am trying to cast a data frame but not aggregate the rows for the
>> same variable.
>>
>> here is a contrived example.
>>
>> **input**
>> temp_df  <- data.frame(names=c('foo','foo','foo'),variable=c('w','w','w'),value=c(34,65,12))
>>> temp_df
>>   names variable value
>> 1   foo        w    34
>> 2   foo        w    65
>> 3   foo        w    12
>>
>>
>> ###########
>> **Want this**
>> ############
>> names  w
>> foo         34
>> foo         65
>> foo         12
>>
>>
>> ##
>> **getting this***
>> ##
>>> cast(temp_df)
>> Aggregation requires fun.aggregate: length used as default
>>   names w
>> 1   foo 3
>>
>>
>> In real dataset  the categorical column 'variable' will have many more
>> categorical variable.
>>
>> Thanks!
>> -Abhi
>>
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>>