matrix multiplication is something weāve all done at some point.

while some of yāall still do stuff that require matrix multiplication, most of yāall donāt

none the less if youāre reading this youāre curious why we do

answering that would need some digging into the **concept of matrix(s)**

`spoiler: it's really intuitive once you remember that matrices represent something`

hereās a video version of this blog post https://youtu.be/hVZD4OvlV3w

# what does a matrix represent?

a matrix is a **2d tensor**

a tensor is an n-dimentional array that holds different values for different parameters of the array

pretty sure that definition doesnāt help but **think** of a **matrix** to be an *excel/SQL **table***

letās take an example: list of items in my bag, converting that from a table to a matrix would look like:

this is technically an **array**, but to make this a matrix, letās add one dimension i.e, parameter to the array

*ohh this is the computer science representation of a matrix by the way*

the math representation is pretty straight forward, remove the tables and draw those brackets š

# what about matrix multiplication?

just remembering that the matrix represents something and performing normal multiplication keeping in mind the parameters should make you intuitively perform that pattern

donāt believe em?? letās run through an example

hereās the distances Suraj and Arjun travelled in the months of jan, feb and march and hereās the petrol prizes for the months

now calculate the total money spent on petrol by both Suraj and Arjun **without thinking about matrices**

now try with the matrix multiplication method

this is also **why the inner dimensions have to match**, i,e they have to be the same parameters to make sense in terms of what we are multiplying

@ is the symbol for matrix multiplication in python

and why the shape of the result is the outer dimension

untill next time !ļø ā

or you could spot me in the wild š¤ i mean instagram, twitter, linkedin and maybe even youtube where i excalidraw those diagrams