问题
I have the following data frame:
df <- data.frame(Return1=c(NA, NA, .03, .04, .05),
Return2=c(.25, .33, NA, .045, .90),
Return3=c(.04, .073, .08, .04, .01))
Return1 Return2 Return3
1 NA 0.250 0.040
2 NA 0.330 0.073
3 0.03 NA 0.080
4 0.04 0.045 0.040
5 0.05 0.900 0.010
I would like to compute the cumulative returns, but there are missing values in the dataframe. I used:
cumprod(df+1)-1
Getting as a result
Return1 Return2 Return3
1 NA 0.2500 0.0400000
2 NA 0.6625 0.1159200
3 NA NA 0.2051936
4 NA NA 0.2534013
5 NA NA 0.2659354
The problem here is that if there is a NA, the subsequent rows down will have as a Result NA. Is there a way to compute the cumulative returns without NA's affecting the rest of the rows below?
I would like to obtain as a result:
Return1 Return2 Return3
1 NA 0.2500 0.0400000
2 NA 0.6625 0.1159200
3 0.03 NA 0.2051936
4 0.07120 0.7373 0.2534013
5 0.12476 2.3008 0.2659354
I know of a function in the PerformanceAnalytics package called Return.cumulative,but this will only obtain the cumulative return of the entire columns.
Any ideas?
回答1:
cumpfun <- function(x){
x[!is.na(x)] <- cumprod(x[!is.na(x)]+1)-1
x
}
sapply(df,cumpfun)
# Return1 Return2 Return3
# [1,] NA 0.2500000 0.0400000
# [2,] NA 0.6625000 0.1159200
# [3,] 0.03000 NA 0.2051936
# [4,] 0.07120 0.7373125 0.2534013
# [5,] 0.12476 2.3008937 0.2659354
Note that sapply
returns a matrix. If you need a data frame, you could use sth like as.data.frame(lapply(df, cumpfun))
来源:https://stackoverflow.com/questions/25574199/cumulative-returns-with-nas-in-r