N-D arrays that have the right amount of singleton dimensions but they're in the wrong order (#1). Vectors where a dimension is a multiple of the same dimension in the other array.Īrrays with dimensions that are multiples of each other. # Examples of incompatible sizes: Description In other words - dimensions that appear in one array and do not appear in the other, are implicitly fit for automatic expansion.įor example, in MATLAB versions before R2016b this would happen:Īns = 9 3 9 4 7 10 5 11 5 # Examples of compatible sizes: Description Note that trailing singleton (that is, of size 1) dimensions are omitted by MATLAB, even though there's theoretically an infinite amount of them. Sizes are considered 'compatible' when each dimension in one array is either exactly equal to the same dimension in the other array, or is equal to 1. The aforementioned binary operations are allowed between arrays, as long as they have 'compatible sizes'.

Elementary math functions: max, min, mod, rem, hypot, atan2, atan2d.

Bit-wise functions: bitand, bitor, bitxor.

Element-wise arithmetic operators: +,.

The operators that support implicit expansion are 1 (opens new window): MATLAB R2016b featured a generalization of its scalar expansion 1 (opens new window), 2 (opens new window) mechanism, to also support certain element-wise operations between arrays of different sizes, as long as their dimension are compatible. # Implicit array expansion (broadcasting) Internally, bsxfun does not replicate the array and executes an efficient loop. The function, must be a binary function meaning it must take exactly two inputs. In other languages, this is commonly referred to as broadcasting and happens automatically in Python (numpy) and Octave. All conditions are met and B will be replicated to match the 3rd dimension of A. Secondly, A has K layers while B has implicitly only 1, hence it is a singleton. Firstly, their first two dimensions have corresponding sizes. After the expansion, a binary function is applied elementwise on the two arrays.įor example, let A be an M-by- N-by K array and B is an M-by- N array.

Then the array with the singleton dimension will be expanded to match the dimension of the other array. has a size of 1) in either of the two arrays and the discordant dimension is a singleton (i.e.two arrays share the same dimensions except for one.

The name bsxfun helps to understand how the function works and it stands for Binary FUNction with Singleton e Xpansion. Where is one of the supported functions (opens new window) and the two arrays A and B respect the two conditions below. Ordinary Differential Equations (ODE) Solvers.Fourier Transforms and Inverse Fourier Transforms.Get the value of a function of two or more arguments.Implicit array expansion (broadcasting).

Matlab vectorize a matrix