Reputation: 68
I am building a time series (xts) from several observations stored in a list of xts objects. The extracted data is missing sometimes, R report the error:
"Error in NextMethod(.Generic) : replacement has length zero"
I would like R to report NA instead. I guess the answer lies in tryCatch(), but I'm unable to nail it.
# Here is a MCVE:
Contract <- list(xts(1:12,order.by=Sys.Date()-1:12),
xts(1:10,order.by=Sys.Date()-1:10),
xts(1:8,order.by=Sys.Date()-2:9))
Vol <- xts(matrix(0, 12,3, byrow = FALSE),order.by=Sys.Date()-1:12)
for (A in 1:12){for (B in 1:3){
Vol[A,B] <- Contract[[B]][index(Vol)[A]]
}}
Vol
Any help would be gladly appreciated. (Also, if someone as clever idea to vectorize the double loop...)
Upvotes: 2
Views: 86
Reputation: 72974
We could check if coercing the generated observation into numeric yields numeric(0)
.
Here is a solution with sapply()
that creates the matrix out of a vector of all dates.
all.dates <- Sys.Date() - 1:12
MX <- t(sapply(seq_along(all.dates), function(x)
sapply(seq_along(Contract), function(y) {
obs <- Contract[[y]][all.dates[x]]
if (identical(as.numeric(obs), numeric(0))) # reporting NA
xts(NA, all.dates[x])
else
obs
}
)))
Vol <- xts(MX, order.by=all.dates)
rm(MX) # clean up
> Vol
[,1] [,2] [,3]
2019-01-09 12 NA NA
2019-01-10 11 NA NA
2019-01-11 10 10 NA
2019-01-12 9 9 8
2019-01-13 8 8 7
2019-01-14 7 7 6
2019-01-15 6 6 5
2019-01-16 5 5 4
2019-01-17 4 4 3
2019-01-18 3 3 2
2019-01-19 2 2 1
2019-01-20 1 1 NA
Could you please check if this is the result you expect?
Upvotes: 1