Fact: We cannot take the inner product of two vectors of different dimensionality.

We illustrate this with an example next.

using LinearAlgebra: dot

$a=[1,2,3,5]$

$b=[4,5,6]$

dot$(b,a)$

Run

T Revert

$$ Code errored $(15ms)$

LoadError: DimensionMismatch$("$first array has length $3$ which does not match the length of the second, $4.")$

DimensionMismatch$("$first array has length $3$ which does not match the length of the second, $4.")$

Stacktrace:

$[1]$ Array Int$64,1\},$ ::Array Int$64,1\})$ at

$/$buildworker$/$worker$/$package$\_$linux$64/$build$/$usr$/$share$/$julia$/$stdlib$/$v$1\mathrm{.}5/$Line arAlgebra$/$src$/$generic$.$jl:$889$

$[2]$ top$-$level scope at In $[28]$:$5$