calcLagged: Replaces the values in a vector with the result of applying an operation to it
and a lagged value
Description
Replaces the values in x with the result of applying an
operation to it and the value that is lag positions
either before it or after it in x, depending on whether
lag is positive or negative. For positive lag
the first lag values will be NA, while for negative
lag the last lag values will be NA.
When operation is NULL, the values are moved
lag positions down the vector.
Usage
calcLagged(x, operation = NULL, lag = 1)
Arguments
x
A vector containing the values on which the calculations are to be made.
operation
A character giving the operation to be performed on pairs of
values in x. If operation is NULL then the values are moved
lag positions down the vector.
lag
A integer specifying, for the second value in the pair to be operated on,
the number positions it is ahead of or behind the current value.
Value
A vector containing the result of applying operation to
values in x. For positive lag the first lag values will
be NA, while for negative lag the last lag values will be NA.