raply {plyr}

Replicate expression and return results in a array.

Description

Evalulate expression n times then combine results into an array

Usage

raply(.n, .expr, .progress = "none", .drop = TRUE)

Arguments

.n

number of times to evaluate the expression

.expr

expression to evaluate

.progress

name of the progress bar to use, see create_progress_bar

.drop

should extra dimensions of length 1 be dropped, simplifying the output. Defaults to TRUE

Details

This function runs an expression multiple times, and combines the result into a data frame. If there are no results, then this function returns a vector of length 0 (vector(0)). This function is equivalent to replicate, but will always return results as a vector, matrix or array.

Value

if results are atomic with same type and dimensionality, a vector, matrix or array; otherwise, a list-array (a list with dimensions)

References

Hadley Wickham (2011). The Split-Apply-Combine Strategy for Data Analysis. Journal of Statistical Software, 40(1), 1-29. https://www.jstatsoft.org/v40/i01/.

Examples

raply(100, mean(runif(100)))
raply(100, each(mean, var)(runif(100)))

raply(10, runif(4))
raply(10, matrix(runif(4), nrow=2))

# See the central limit theorem in action
hist(raply(1000, mean(rexp(10))))
hist(raply(1000, mean(rexp(100))))
hist(raply(1000, mean(rexp(1000))))