# lag.zoo

##### Lags and Differences of zoo Objects

Methods for computing lags and differences of `"zoo"`

objects.

- Keywords
- ts

##### Usage

```
## S3 method for class 'zoo':
lag(x, k = 1, na.pad = FALSE, \dots)
## S3 method for class 'zoo':
diff(x, lag = 1, differences = 1, arithmetic = TRUE, na.pad = FALSE, \dots)
```

##### Arguments

- x
- a
`"zoo"`

object. - k, lag
- the number of lags (in units of observations).
Note the sign of
`k`

behaves as in`lag`

. - differences
- an integer indicating the order of the difference.
- arithmetic
- logical. Should arithmetic (or geometric) differences be computed?
- na.pad
- logical. If
`TRUE`

it adds any times that would not otherwise have been in the result with a value of`NA`

. If`FALSE`

those times are dropped. - ...
- currently not used.

##### Details

These methods for `"zoo"`

objects behave analogously to the default
methods. The only additional arguments are `arithmetic`

in `diff`

`na.pad`

in `lag.zoo`

which can also be specified in `diff.zoo`

as part of the dots.
Also, `"k"`

can be a vector of lags in which case the names of
`"k"`

, if any, are used in naming the result.

##### Value

- The lagged or differenced
`"zoo"`

object.

##### Note

Note the sign of `k`

: a series lagged by a positive `k`

is shifted *earlier* in time.

`lag.zoo`

and `lag.zooreg`

can give different results.
For a lag of 1 `lag.zoo`

moves points to the adjacent time point
whereas `lag.zooreg`

moves the time by `deltat`

. This
implies that a point in a `zoo`

series cannot be lagged to a time
point that is not already in the series whereas this is possible for
a `zooreg`

series.

##### See Also

##### Examples

```
x <- zoo(11:21)
lag(x, k = 1)
lag(x, k = -1)
# this pairs each value of x with the next or future value
merge(x, lag1 = lag(x, k=1))
diff(x^2)
diff(x^2, na.pad = TRUE)
```

*Documentation reproduced from package zoo, version 1.5-6, License: GPL-2*