What is the reason behind this behavior? Type stability? I had expected this to either yield a two by zero matrix or throw an error. julia> A = zeros( 2, 0 ) 2×0 Matrix{Float64} julia> B = zeros( 0, ) Float64[] julia> A * B 2-element Vector{Float64}: 0.0 0.0

Zero matrices are the conventional outputs of multiplying empty matrices . The column-major Vector with length N is treated as a column vector corresponding to a Nx1 matrix. Multiplying a MxN matrix by a Nx1 matrix is expected to make a Mx1 matrix, and given matrix-vector multiplication, the output i…

Matrix with zero columns multiplied by vector with zero elements yields vector

General Usage

Joris_Pinkse August 11, 2025, 1:26am 4

It isn’t a problem. It’s in fact convenient to me.

Topic		Replies	Views
Inconsistency between zero(x) and zero(T::Type) for matrices Internals & Design	6	518	April 6, 2022
How to make `[0] == 0`? General Usage question , syntax	24	1141	April 29, 2024
Vector*matrix in 0.6 General Usage	16	2926	February 2, 2017
Why does Julia support `::Vector * ::Matrix`? General Usage question , linearalgebra	7	586	December 9, 2023
Function zero() with type"Any" General Usage question	14	5976	March 2, 2020

Matrix with zero columns multiplied by vector with zero elements yields vector

Related topics