# sweep

##### Sweep out Array Summaries

Return an array obtained from an input array by sweeping out a summary statistic.

##### Usage

`sweep(x, MARGIN, STATS, FUN = "-", check.margin = TRUE, …)`

##### Arguments

- x
an array.

- MARGIN
a vector of indices giving the extent(s) of

`x`

which correspond to`STATS`

.- STATS
the summary statistic which is to be swept out.

- FUN
the function to be used to carry out the sweep.

- check.margin
logical. If

`TRUE`

(the default), warn if the length or dimensions of`STATS`

do not match the specified dimensions of`x`

. Set to`FALSE`

for a small speed gain when you*know*that dimensions match.- …
optional arguments to

`FUN`

.

##### Details

`FUN`

is found by a call to `match.fun`

. As in the
default, binary operators can be supplied if quoted or backquoted.

`FUN`

should be a function of two arguments: it will be called
with arguments `x`

and an array of the same dimensions generated
from `STATS`

by `aperm`

.

The consistency check among `STATS`

, `MARGIN`

and `x`

is stricter if `STATS`

is an array than if it is a vector.
In the vector case, some kinds of recycling are allowed without a
warning. Use `sweep(x, MARGIN, as.array(STATS))`

if `STATS`

is a vector and you want to be warned if any recycling occurs.

##### Value

An array with the same shape as `x`

, but with the summary
statistics swept out.

##### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
*The New S Language*.
Wadsworth & Brooks/Cole.

##### See Also

`apply`

on which `sweep`

used to be based;
`scale`

for centering and scaling.

##### Examples

`library(base)`

```
# NOT RUN {
require(stats) # for median
med.att <- apply(attitude, 2, median)
sweep(data.matrix(attitude), 2, med.att) # subtract the column medians
## More sweeping:
A <- array(1:24, dim = 4:2)
## no warnings in normal use
sweep(A, 1, 5)
(A.min <- apply(A, 1, min)) # == 1:4
sweep(A, 1, A.min)
sweep(A, 1:2, apply(A, 1:2, median))
## warnings when mismatch
sweep(A, 1, 1:3) # STATS does not recycle
sweep(A, 1, 6:1) # STATS is longer
## exact recycling:
sweep(A, 1, 1:2) # no warning
sweep(A, 1, as.array(1:2)) # warning
# }
```

*Documentation reproduced from package base, version 3.5.2, License: Part of R 3.5.2*