Hi,
I think you overthought this one a little bit, I don't know if this is the
kind of code you are expecting but I came up with something like that:
generate_transition_matrix <- function(data, n_states) {
#To be sure I imagine you should check n_states is right at this point
transitions <- matrix(0, n_states, n_states)
#we could improve a little bit here because at step N+1 source is dest
from step N
#but it would not be as readable
for (k in 1:(length(data) - 1)) {
source_state <- data[k]
dest_state <- data[k+1]
transitions[source_state, dest_state] <- transitions[source_state,
dest_state] + 1
}
for (k in 1:n_states)
transitions[k,] <- transitions[k,] / sum(transitions[k,])
transitions
}
checkdf=data.frame(clusterNum=c(3,2,3,1,1,3,4,3,2,1,1,3,2,1,3,2))
no_of_state=4
transition_matrix= generate_transition_matrix(checkdf$clusterNum,
no_of_state)
transition_matrix
2017-08-28 16:37 GMT+02:00 niharika singhal <niharikasinghal1...@gmail.com>:
> Hello,
>
> I am trying to implement a formula
>
> aij= transition from state S_i to S_j/no of transition at state S_i
>
>
>
> Code I have written is working with three state {1,2,3 }, but if the number
> of states become={1,2,3,4,......n} then the code will not work, so can some
> help me with this.
>
> For and some rows of my data frame look like
>
> checkdf=data.frame(clusterNum=c(3,2,3,1,1,3,4,3,2,1,1,3,2,1,3,2)
> no_of_state=3
> transition_matrix=matrix(NA,nrow=no_of_state, ncol=no_of_state)
> for(k in 1: no_of_state)
> {
> count1=0
> count2=0
> count3=0
> #For last point no transition takes place
> for(j in 1: (nrow(checkdf)-1))
> {
>
> if(checkdf$clusterNum[j]==k)
> {
> if(checkdf$clusterNum[j+1]==1){
> count1=count1+1
> }
> else if(checkdf$clusterNum[j+1]==2){
> count2=count2+1
> }
> else {
> count3=count3+1
> }
> }
> }
>
> no_of_points=(count1+count2+count3)
> s1=count1/no_of_points
> s2=count2/no_of_points
> s3=count3/no_of_points
> transition_matrix[k,]=c(s1, s2, s3)
>
> }
>
> I know the code is not written nicely and I want to improve it.
>
> Thanks in advance
> Niharika
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/
> posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
