Apply.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/Apply.R
\name{Apply}
\alias{Apply}
\title{Wrapper for Applying Atomic Functions to Arrays.}
\usage{
Apply(data, margins = NULL, AtomicFun, ..., parallel = FALSE,
  ncores = NULL)
}
\arguments{
\item{data}{A single numeric object (vector, matrix or array) or a list of numeric objects. They must be in the same order as expected by AtomicFun.}

\item{margins}{List of vectors containing the margins for the input objects to be split by. Or, if there is a single vector of margins specified and a list of objects in data, then the single set of margins is applied over all objects.}

\item{AtomicFun}{Function to be applied to the arrays.}

\item{...}{Additional arguments to be used in the AtomicFun.}

\item{parallel}{Logical, should the function be applied in parallel.}

\item{ncores}{The number of cores to use for parallel computation.}
}
\value{
Array or matrix or vector resulting from AtomicFun.
}
\description{
When using a single numeric object as input, Apply is almost identical to the apply function. For multiple input objects, the output array 
will have dimensions equal to the dimensions specified in 'margins'.
}
\details{
A user can apply a function that receives 1 or more numeric objects as input, each with a different number of dimensions, and returns as a result a single array with any number of dimensions.
}
\examples{
#Change in the rate of exceedance for two arrays, with different 
#dimensions, for some matrix of exceedances.
array_1 <- array(rnorm(2000), c(10,10,20)) # array with 20 timesteps
array_2 <- array(rnorm(1000), c(10, 10, 15)) # array with 15 timesteps
thresholds <- matrix(rnorm(100), 10, 10) # matrix of thresholds (no timesteps)

# Function for calculating the change in the frequency of exceedances over the
#thresholds for array_1 relative to array_2 (percentage change).

test_fun <- function(x, y, z) {(((sum(x > z) / (length(x))) / 
                                (sum(y > z) / (length(y)))) * 100) - 100}
data = list(array_1, array_2, thresholds)
margins = list(c(1, 2), c(1, 2), c(1,2))
test <- Apply(data, margins, AtomicFun = "test_fun")
}
\references{
Wickham, H (2011), The Split-Apply-Combine Strategy for Data Analysis, Journal of Statistical Software.
}