base (version 3.3.1)

# sum: Sum of Vector Elements

## Description

`sum` returns the sum of all the values present in its arguments.

## Usage

`sum(..., na.rm = FALSE)`

## Arguments

...
numeric or complex or logical vectors.
na.rm
logical. Should missing values (including `NaN`) be removed?

## Value

The sum. If all of `...` are of type integer or logical, then the sum is integer, and in that case the result will be `NA` (with a warning) if integer overflow occurs. Otherwise it is a length-one numeric or complex vector.NB: the sum of an empty set is zero, by definition.

## S4 methods

This is part of the S4 `Summary` group generic. Methods for it must use the signature `x, ..., na.rm`. ‘plotmath’ for the use of `sum` in plot annotation.

## Details

This is a generic function: methods can be defined for it directly or via the `Summary` group generic. For this to work properly, the arguments `...` should be unnamed, and dispatch is on the first argument.

If `na.rm` is `FALSE` an `NA` or `NaN` value in any of the arguments will cause a value of `NA` or `NaN` to be returned, otherwise `NA` and `NaN` values are ignored.

Logical true values are regarded as one, false values as zero. For historical reasons, `NULL` is accepted and treated as if it were `integer(0)`.

Loss of accuracy can occur when summing values of different signs: this can even occur for sufficiently long integer inputs if the partial sums would cause integer overflow. Where possible extended-precision accumulators are used, but this is platform-dependent.

## References

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

`colSums` for row and column sums.

## Examples

```
## Pass a vector to sum, and it will add the elements together.
sum(1:5)

## Pass several numbers to sum, and it also adds the elements.
sum(1, 2, 3, 4, 5)

## In fact, you can pass vectors into several arguments, and everything gets added.
sum(1:2, 3:5)

## If there are missing values, the sum is unknown, i.e., also missing, ....
sum(1:5, NA)
## ... unless  we exclude missing values explicitly:
sum(1:5, NA, na.rm = TRUE)
```