I have a function to calculate the rate of increase (the difference between
the value and the previous value divided by the total number of eggs in a
year) of egg production over the course of a year:
rate <- function(x){
storage <- matrix(nrow=length(x),ncol=1)
storage[1,] <- x[1] / max(x) # as there is no previous value
for( i in 2:length(x)){
p <- i - 1
storage[i,] <- ((x[i] - x[p] / max(x))
}
return(storage)
}
However, as it requires the subtraction of one term with the previous term
it fails when dealing with objects with length = 1 (when only one reading
has been taken in a year). I have tried adding an ifelse() function into
`rate' with NA added for length 1:
rate <- function(x){
storage <- matrix(nrow=length(x),ncol=1)
ifelse(length(x)==1,storage[1,] <- NA,{
storage[1,] <- x[1]/max(x)
for(i in 2:length(x)){
p <- i-1
storage[i,] <- ((x[i] - x[p]) / max(x))
}
})
return(storage)
}
but I end up with this error when I try and use the above function in
tapply():
Error in ans[!test & !nas] <- rep(no, length.out = length(ans))[!test & :
replacement has length zero
Thanks in advance,
Ben
--
View this message in context:
http://r.789695.n4.nabble.com/error-in-self-made-function-cannot-deal-with-objects-of-length-1-tp3710555p3710555.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
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.
