[R] Method Guidance

[Jeff Reichman]

Rui

Well that certainly is a lot more straight forward than the direction I was trying and you have introduced me to a couple of new functions. Thank you

Jeff

-----Original Message-----
From: Rui Barradas <ruipbarradas using sapo.pt> 
Sent: Wednesday, January 12, 2022 5:08 AM
To: reichmanj using sbcglobal.net; r-help using r-project.org
Subject: Re: [R] Method Guidance

Hello,

Here is a base R solution for what I understand of the question.
It involves ave and cumsum. cumsum of the values of Event_A breaks Event_B in segments and ave applies a function to each segment. To find where are the times B, coerce to logical and have which() take care of it. Data in dput format at the end.



ave(as.logical(df1$Event_B), cumsum(df1$Event_A),
     FUN = function(x) {
       y <- integer(length(x))
       y[x] <- which(x) - 1L
       y
     })
#[1] 0 1 0 0 1 0 3 0 0 2


More readable, with an auxiliary function.


aux_fun <- function(x) {
   y <- integer(length(x))
   y[x] <- which(x) - 1L
   y
}

ave(as.logical(df1$Event_B), cumsum(df1$Event_A), FUN = aux_fun) #[1] 0 1 0 0 1 0 3 0 0 2



Now assign this result to a df1 column. Here I just test for equality.


new <- ave(as.logical(df1$Event_B), cumsum(df1$Event_A), FUN = aux_fun) identical(new, df1$Time_B) #[1] TRUE


# Data
df1 <-
structure(list(Time = 1:10, Event_A = c(1L, 0L, 0L, 1L, 0L, 0L, 0L, 1L, 0L, 0L), Event_B = c(1L, 1L, 0L, 0L, 1L, 0L, 1L, 1L, 0L, 1L), Time_B = c(0L, 1L, 0L, 0L, 1L, 0L, 3L, 0L, 0L, 2L)), class = "data.frame", row.names = c(NA, -10L))



Hope this helps,

Rui Barradas

Às 00:56 de 12/01/22, Jeff Reichman escreveu:
> R-Help Forum
> 
>   
> 
> Looking for a little guidance. Have an issue were I'm trying to 
> determine the time between when Event A happened(In days) to when a 
> subsequent Event B happens. For Example at Time 1 Evat A happens and 
> subsequently Event B happens at the same day (0) and the next day (1) 
> then Event A happens again at time 4 and Event B happens the next day 
> and 3 days later so on and so forth. I gather there is no function 
> that will do that so I suspect I will need to grate so sour of do while loop?  Any suggestions?
> 
>   
> 
>   
> 
> Time      Event_A               Event_B               Time_B
> 
> 1              1                              1
> 0
> 
> 2              0                              1
> 1
> 
> 3              0                              0
> 0
> 
> 4              1                              0
> 0
> 
> 5              0                              1
> 1
> 
> 6              0                              0
> 0
> 
> 7              0                              1
> 3
> 
> 8              1                              1
> 0
> 
> 9              0                              0
> 0
> 
> 10           0                              1                              2
> 
> 
>   
> 
> Jeff Reichman
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help using 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.
>