R help - Nov 2013 - Data transformation to list for event occurence

Hi,

Say I have a following data

ID   Week    Event_Occurence
A 1 0
A 2 0
A 3 1
A 4 0
B 1 1
B 2 0
B 3 0
B 4 1

that whether an individual experienced an event in a particular week.

I wish to create list such as the first element of the list will be a
vector listing the week number when the event has occurred for A, followed
by that of B.

Can you help creating this?

-- 
Anindya Sankar Dey

	[[alternative HTML version deleted]]

Hi Anindya,

You may try:
dat1 <- read.table(text="ID?? Week??? Event_Occurence
A 1 0
A 2 0
A 3 1
A 4 0
B 1 1
B 2 0
B 3 0
B 4 1",sep="",header=TRUE,stringsAsFactors=FALSE)

?with(dat1,tapply(as.logical(Event_Occurence),ID,FUN=which ))
#or
lapply(split(dat1,dat1$ID),function(x) which(!!x[,3]))
A.K.





On Tuesday, November 12, 2013 4:58 PM, Anindya Sankar Dey <anindya55 at
gmail.com> wrote:
Hi,

Say I have a following data

ID?  Week? ? Event_Occurence
A 1 0
A 2 0
A 3 1
A 4 0
B 1 1
B 2 0
B 3 0
B 4 1

that whether an individual experienced an event in a particular week.

I wish to create list such as the first element of the list will be a
vector listing the week number when the event has occurred for A, followed
by that of B.

Can you help creating this?

-- 
Anindya Sankar Dey

??? [[alternative HTML version deleted]]

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