reorient_vector: Change Orientation of An Oriented Vector and Make it a...

In broadcast: Broadcasted Array Operations Like 'NumPy'

Change Orientation of An Oriented Vector and Make it a Broadcaster

Description

The lhs %orientbc<-% rhs operator takes an oriented vector (lhs), and changes its orientation.
It also makes lhs a broadcaster if it wasn't already.

The modification is done directly on lhs itself, using R's native semantics.

Usage

lhs %orientbc<-% rhs

Arguments

lhs	an atomic or recursive oriented vector.
rhs	an integer vector. The first value must be the new orientation, referred to as orient. The second value, optional, must be the number of dimensions, referred to as ndim. If no second value is given, it will be set at max(ndim(lhs), rhs[1]).

Details

In the context of broadcasting, an oriented vector x is a vector or array that satisfies the following conditions:

• It has length ⁠> 1⁠ and ⁠<= (2^31 - 1)⁠;

• It has no dimensions, or one dimension is length(x) and all other dimensions are 1.
  

The orientation of an oriented vector is the index of the dimension with size > 1.
For example, if array lhs has dimensions c(1, 10, 1), its orientation is 2L, since the second dimension has size > 1.
A vector with no dimensions has orientation 1L.

In the context of broadcasted operations, oriented vectors can be used to modify an array along a dimension.
The examples section gives several examples of this.

Value

Nothing, but changes lhs directly.

See Also

broadcast_casting

Examples

# basic usage ====
x <- setNames(1:10, letters[1:10])
print(x)

x %orientbc<-% 2L
print(x)
x %orientbc<-% 3L
print(x)
x %orientbc<-% 1:2
print(x)
x %orientbc<-% c(1, 3)
print(x)



# modify an array along one specific dimension ====
x <- array(sample(0:9), c(3,3,3))
print(x)

# add 10 to second column, and 100 to third column:
v <- vector2array(c(0, 10, 100), 2, 2, TRUE)
x + v

# add 10 to second row, and 100 to third row:
v %orientbc<-% 1L
x + v

# add 10 to second layer, and 100 to third layer:
v %orientbc<-% 3L
x + v

broadcast documentation built on Aug. 20, 2026, 9:08 a.m.