# rvmean: Expectation of a Random Variable In rv: Simulation-Based Random Variable Objects

`rvmean`

## Usage

 ```1 2 3``` ``` rvmean(x) E(x) Pr(X) ```

## Arguments

 `x` an rv object `X` a logical rv object

## Details

`rvmean` computes the means of the simulations of all individual components of a random vector (rv) object.

`E` is an alias for `rvmean`, standing for “Expectation.”

`Pr` is another alias for `rvmean`, standing for “Probability of”; suggested to be used when the argument is a logical statement involving random variables (that is, a description of an event such as `x>0` or `x>y`). Then `Pr(x>0)` gives the probability of the event “x>0”. The statement `x>0` returns a Bernoulli (indicator) random variable object (having 1/0 or TRUE/FALSE values) and the expectation of such variable is just the probability of the event where the indicator is one.

## Value

A numerical vector with the same dimension as `x`.

## Author(s)

Jouni Kerman [email protected]

## References

Kerman, J. and Gelman, A. (2007). Manipulating and Summarizing Posterior Simulations Using Random Variable Objects. Statistics and Computing 17:3, 235-244.

See also `vignette("rv")`.

`mean.rv`: distribution of the arithmetic mean of a vector; `rvmin`, `rvmax`, `rvmedian`, `link{rvvar}`, `rvsd`.
 ```1 2 3 4``` ``` x <- rvnorm(mean=(1:10)/5, sd=1) rvmean(x) # means of the 10 components E(x) # same as rvmean(x) Pr(x>1) # probabilities that each component is >1. ```