[R] Constructing the transition pair using loop function and paste()

[jim holtman]

try this:  You were redfining 'transition' within the loop

x <-
c('A','D','F','H','N','A','C','H','F','D','F','F','H','K','G','D','D','B','N','K','O','V','S','S','F','H','J','U','K','T','H','S','R','G','S','R','R','G','D','B','G','F','G','N','H','H','K','L','B','X','C','V','S','F','X','G','T','H','H','H','R','A','E','D','C')
y <- c(rep(0293,8), rep(0498,6), rep(6847,10), rep(6209,4), rep(8562,13),
rep(4596,6), rep(2857,2), rep(6178,3), rep(6018,5), rep(5629,4),
rep(7535,4))
mydata <- as.data.frame(cbind(x,y))
names(mydata) <- c('actions', 'agents')
mydata

transition <- vector('list', length(unique(mydata$agents)))        #
create a list to hold the outputs

for (i in 1:length(unique(mydata$agents))){         # decompose the
data frame by agents
    agent.i <- mydata[mydata$agents == (unique(mydata$agents))[i], ]
    transit.i <- c()
    for (j in 1:length(agent.i$actions)-1){
        transit.i[j] <- paste(agent.i$actions[j],
agent.i$actions[j+1], sep = '')
    }
    # for each subset of each agent, perform the 'pairing'
    transition[[i]] <- transit.i
}
transition

On Thu, Oct 20, 2011 at 8:52 AM, Sally Zhen <saliluna at gmail.com> wrote:
> Hi all,
>
>
> I'd like to thank those who helped me with my previous loop function
> question with agents/events. I have solved the problem with the advice from
> this community.
>
> I have now moved on to the next step, which requires me to find all the
> transition pair within an event. A sample data and the R commands I've
> written are as follow:
>
> x <-
> c('A','D','F','H','N','A','C','H','F','D','F','F','H','K','G','D','D','B','N','K','O','V','S','S','F','H','J','U','K','T','H','S','R','G','S','R','R','G','D','B','G','F','G','N','H','H','K','L','B','X','C','V','S','F','X','G','T','H','H','H','R','A','E','D','C')
> y <- c(rep(0293,8), rep(0498,6), rep(6847,10), rep(6209,4), rep(8562,13),
> rep(4596,6), rep(2857,2), rep(6178,3), rep(6018,5), rep(5629,4),
> rep(7535,4))
> mydata <- as.data.frame(cbind(x,y))
> names(mydata) <- c('actions', 'agents')
> mydata
>
>
> for (i in 1:length(unique(mydata$agents))){         # decompose the data
> frame by agents
> agent.i <- mydata[mydata$agents == (unique(mydata$agents))[i], ]
> transition <- vector('list', length(unique(mydata$agents)))        # create
> a list to hold the outputs
> transit.i <- c()
> for (j in 1:length(agent.i$actions)-1){
> transit.i[j] <- paste(agent.i$actions[j], agent.i$actions[j+1], sep = '')}
>   # for each subset of each agent, perform the 'pairing'
> transition[[i]] <- transit.i}
> transition
>
>
> The actions are ordered, so what I need to do is just to paste each action
> to the next one to form a pair.
> My attempt only produced the desired result for the last agent:
>
> [[1]]
> NULL
>
> [[2]]
> NULL
>
> [[3]]
> NULL
>
> [[4]]
> NULL
>
> [[5]]
> NULL
>
> [[6]]
> NULL
>
> [[7]]
> NULL
>
> [[8]]
> NULL
>
> [[9]]
> NULL
>
> [[10]]
> NULL
>
> [[11]]
> [1] "AE" "ED" "DC"
>
>
> Is there any way to avoid using 2-level loop function, although to me it's
> the most intuitive method? Any pointer would be greatly appreciated!
>
> Regards,
> Sally
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?