bcapply

Apply Function to Pair of Arrays with Broadcasting

Description

The bcapply() method applies a function to 2 arrays element-wise with broadcasting.

Usage

bcapply(x, y, f, ...)

## S4 method for signature 'ANY'
bcapply(x, y, f, v = NULL)

Arguments

x, y conformable atomic or recursive vectors/arrays.
f a function that takes in exactly 2 arguments, and returns a result that can be stored in a single element of a recursive or atomic array.
โ€ฆ further arguments passed to or from methods.

v either NULL, or single string, giving the scalar type for a single iteration.
If NULL (default) or โ€œlistโ€, the result will be a recursive array.
If it is certain that, for every iteration, f() always results in a single atomic scalar of exactly a specific type, the user can specify the type in v to pre-allocate the result.
Pre-allocating the results leads to slightly faster and more memory efficient code.
NOTE: Incorrectly specifying v leads to undefined behaviour;
when unsure, leave v at its default value.

Value

An atomic or recursive array with dimensions bc_dim(x, y).
Preserves some of the attributes of x and y similar to broadcasted infix operators, as explained in broadcast_operators.

Examples

library("broadcast")



# check for each element in one recursive array if values are present in another:
mylist <- list(
  as.raw(0:255),
  sample(c(TRUE, FALSE, NA), 100, TRUE),
  0:255,
  rnorm(10),
  rnorm(10) + rnorm(10) * -1i,
  sample(month.abb)
)
mylist <- c(mylist, list(mylist))
x <- array(sample(mylist, 50, TRUE), c(5, 5, 2))
y <- array(sample(mylist, 50, TRUE), c(5, 5, 2))

bcapply(x, y, `%in%`) # returns a dimensional list / recursive array
## , , 1
## 
##      [,1]        [,2]        [,3]        [,4]        [,5]       
## [1,] logical,256 logical,256 logical,10  logical,100 logical,10 
## [2,] logical,10  logical,256 logical,10  logical,10  logical,10 
## [3,] logical,100 logical,256 logical,6   logical,100 logical,6  
## [4,] logical,256 logical,256 logical,256 logical,10  logical,256
## [5,] logical,10  logical,12  logical,10  logical,12  logical,256
## 
## , , 2
## 
##      [,1]        [,2]        [,3]        [,4]        [,5]       
## [1,] logical,100 logical,12  logical,6   logical,12  logical,256
## [2,] logical,12  logical,12  logical,100 logical,256 logical,10 
## [3,] logical,6   logical,256 logical,100 logical,256 logical,10 
## [4,] logical,256 logical,100 logical,10  logical,6   logical,100
## [5,] logical,10  logical,10  logical,6   logical,256 logical,10

bcapply(x, y, \(x, y) any(x %in% y), v = "logical") # returns logical array
## , , 1
## 
##       [,1]  [,2]  [,3]  [,4]  [,5]
## [1,] FALSE  TRUE FALSE FALSE FALSE
## [2,] FALSE FALSE FALSE FALSE FALSE
## [3,]  TRUE FALSE FALSE  TRUE  TRUE
## [4,]  TRUE FALSE FALSE FALSE FALSE
## [5,] FALSE  TRUE FALSE FALSE  TRUE
## 
## , , 2
## 
##       [,1]  [,2]  [,3]  [,4]  [,5]
## [1,] FALSE  TRUE FALSE  TRUE FALSE
## [2,] FALSE FALSE  TRUE  TRUE FALSE
## [3,] FALSE FALSE FALSE  TRUE FALSE
## [4,] FALSE  TRUE FALSE FALSE FALSE
## [5,] FALSE FALSE FALSE FALSE FALSE

bcapply(x, y, \(x, y) all(x %in% y), v = "logical") # returns logical array
## , , 1
## 
##       [,1]  [,2]  [,3]  [,4]  [,5]
## [1,] FALSE FALSE FALSE FALSE FALSE
## [2,] FALSE FALSE FALSE FALSE FALSE
## [3,] FALSE FALSE FALSE  TRUE  TRUE
## [4,] FALSE FALSE FALSE FALSE FALSE
## [5,] FALSE  TRUE FALSE FALSE  TRUE
## 
## , , 2
## 
##       [,1]  [,2]  [,3]  [,4]  [,5]
## [1,] FALSE  TRUE FALSE  TRUE FALSE
## [2,] FALSE FALSE FALSE FALSE FALSE
## [3,] FALSE FALSE FALSE FALSE FALSE
## [4,] FALSE FALSE FALSE FALSE FALSE
## [5,] FALSE FALSE FALSE FALSE FALSE



# calculate quartiles for each list item, and return numeric array of quartiles:
x <- list(
  a = 1:10,
  beta = exp(-3:3),
  logic = c(TRUE,FALSE,FALSE,TRUE)
)
print(x)
## $a
##  [1]  1  2  3  4  5  6  7  8  9 10
## 
## $beta
## [1]  0.04978707  0.13533528  0.36787944  1.00000000  2.71828183  7.38905610
## [7] 20.08553692
## 
## $logic
## [1]  TRUE FALSE FALSE  TRUE
quantiles <- array(c(1:3/4), c(1, 3))
colnames(quantiles) <- paste0("q = ", quantiles)
print(quantiles)
##      q = 0.25 q = 0.5 q = 0.75
## [1,]     0.25     0.5     0.75

out <- bcapply(x, quantiles, \(x, y) quantile(x, probs = y), v = "double")
print(out)
##        q = 0.25 q = 0.5 q = 0.75
## a     3.2500000     5.5 7.750000
## beta  0.2516074     1.0 5.053669
## logic 0.0000000     0.5 1.000000
typeof(out)
## [1] "double"