weighted.mean {stats} | R Documentation |

## Weighted Arithmetic Mean

### Description

Compute a weighted mean.

### Usage

```
weighted.mean(x, w, ...)
## Default S3 method:
weighted.mean(x, w, ..., na.rm = FALSE)
```

### Arguments

`x` |
an object containing the values whose weighted mean is to be computed. |

`w` |
a numerical vector of weights the same length as |

`...` |
arguments to be passed to or from methods. |

`na.rm` |
a logical value indicating whether |

### Details

This is a generic function and methods can be defined for the first
argument `x`

: apart from the default methods there are methods
for the date-time classes `"POSIXct"`

, `"POSIXlt"`

,
`"difftime"`

and `"Date"`

. The default method will work for
any numeric-like object for which `[`

, multiplication, division
and `sum`

have suitable methods, including complex vectors.

If `w`

is missing then all elements of `x`

are given the
same weight, otherwise the weights
are normalized to sum to one (if possible: if
their sum is zero or infinite the value is likely to be `NaN`

).

Missing values in `w`

are not handled specially and so give a
missing value as the result. However, zero weights *are* handled
specially and the corresponding `x`

values are omitted from the
sum.

### Value

For the default method, a length-one numeric vector.

### See Also

### Examples

```
## GPA from Siegel 1994
wt <- c(5, 5, 4, 1)/15
x <- c(3.7,3.3,3.5,2.8)
xm <- weighted.mean(x, wt)
```

*stats*version 4.4.1 Index]