then try the following:
Atr <- cbind(rep(1:0, each = 4), 1, c(1, rep(0, 7)), 1)
Atr <- rbind(c(0, 1, 0, 1), Atr)
apply(Atr, 2, function (x) {
rr <- rle(x)
if (tail(rr$values, 1) == 0) tail(rr$length, 1) else 0
})
I hope this what you're looking for.
Best,
Dimitris
Mario Lavezzi wrote:
Hi Dimitris, thank you very much.
Actually, I have not specified the following: i want to consider only
the "most recent" sequence of zeros, that is the last part of the time
series.
That is, If I have:
[,1] [,2] [,3] [,4]
[1,] 0 1 0 1
[2,] 1 1 1 1
[3,] 1 1 0 1
[4,] 1 1 0 1
[5,] 1 1 0 1
[6,] 0 1 0 1
[7,] 0 1 0 1
[8,] 0 1 0 1
[9,] 0 1 0 1
I want to store the values (4 0 7 0) in unSpells. That is the values
that represent the "last" sequence of zeros (that is I want to ignore
other possible zeros like the ones I have inserted above).
thanks!
Mario
Dimitris Rizopoulos wrote:
it's not totally clear to me what exactly do you need in this case,
but have a look at the following:
Atr <- cbind(rep(1:0, each = 4), 1, c(1, rep(0, 7)), 1)
unSpells <- colSums(Atr == 0)
unSpells[unSpells == 0] <- 1
unSpells
I hope it helps.
Best,
Dimitris
Mario Lavezzi wrote:
Hello,
I have the following problem.
I am running simulations on possible states of a set of agents
(1=employed, 0=unemployed).
I store these simulated time series in a matrix like the following,
where rows indicates time periods, columns the number of agents (4
agents and 8 periods in this case):
Atr=[
1 1 1 1
1 1 0 1
1 1 0 1
1 1 0 1
0 1 0 1
0 1 0 1
0 1 0 1
0 1 0 1]
At this point, I need to update a vector ("unSpells") which contains
the lenghts of unemployment spells, and is initialized with ones.
Practically, in the case represented I need to store the value "4" at
position 1 of unSpells and "7" at position 3 of unSpells (that is, I
care only of those who, in the last row, are zeros).
I am doing this in the following way (tt+1 indicates the time period
reached by the simulation, n the number of agents):
unSpells = matrix(1,nrow=1,ncol=n)
ppp=apply(Atr[1:(tt+1),],2,rle)
for(i in (1:n)[Atr[tt+1,]==0]){
unSpells[i]=tail(ppp[[i]]$lengths,1)
}
It works, but the for (i in ...) loop slows down the simulation a lot.
Any suggestion on how to avoid this loop? (or in general, to speed up
this part of the simulation)
Thanks!!
Mario
--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center
Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
______________________________________________
R-help@r-project.org mailing list
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.
