Does a R package exist which implements a circular array or vector in the sense of FIFO?
Say we have this array:
2 4 7 1
When inserting a new observation(say 3) at position 1, I want the n-th element to be replaced with the n-1st element:
3 2 4 7
You could try c() and cut off the length of the result.
x <- c(2, 4, 7, 1)
c(3, x)[1:length(x)]
# [1] 3 2 4 7
This method does not make any copies of x
tracemem(x)
# [1] "<0x3cb5998>"
c(3, x)[1:length(x)]
# [1] 3 2 4 7
untracemem(x)
The source code for append() looks like it might have some useful methods to try out as well.
append
# function (x, values, after = length(x))
# {
# lengx <- length(x)
# if (!after)
# c(values, x)
# else if (after >= lengx)
# c(x, values)
# else c(x[1L:after], values, x[(after + 1L):lengx])
# }
# <bytecode: 0x31ac490>
# <environment: namespace:base>