Hi,
I need some help improving this ugly code I wrote. I would like to shift
forward a zoo object, matrix, ts, or list by "shift" items (default 1) and
fill the holes with 0's.
The code below works, but it looks ugly. I could write a function
lag.zerofill() which calls the two functions below depending on the class()
of the item passed in, but that feels very unlike R.
What is the proper way to write this code so that it works for all input
types?
Is a switch depending on the input type really necessary? I am hoping the
answer is "no".
Thanks in advance.
- Ken
#
-----------------------------------------------------------------------------------
require( zoo );
inp <- c( 5, 9, 4, 2, 1 ); inp2 <- c( 6, 6, 0, 4, 2 );
inp.zoo <- zoo( cbind( inp, inp2 ), as.Date("2003-02-01") +
(0:(length(inp)-1)));
lag.zerofill.list <- function( m, shift=1, ...) {
c( rep(0,shift), m[-((length(m)-shift+1):length(m))] );
}
lag.zerofill.zoo <- function( m, shift=1, ...) {
k <- rbind( m[1:shift,], lag(m,-(shift))); k[1:shift,] <- 0; k;
}
lag.zerofill.list( inp ) # works ok
lag.zerofill.zoo( inp.zoo ) # works ok