Vector Space Codimension

In the context of a finite-dimensional vector space V over a field K, and a subspace W of V, the codimension is the difference between the dimensions of the space V and the subspace W.
$$ codim_k(W) = dim_k(V) - dim_k(W) $$

The codimension is denoted by the notation codim or codimk.

If the field is clear from context, the specific mention of field k can be omitted.

Note. The dimension of a vector space or a subspace is always a non-negative integer. Thus, the codimension is also a non-negative integer.

What is the Purpose of Codimension?

Codimension is a ratio between the vector space and its subspace.

It measures how many times smaller the subspace W is compared to the vector space V that contains it.

 

 
 

Please feel free to point out any errors or typos, or share suggestions to improve these notes. English isn't my first language, so if you notice any mistakes, let me know, and I'll be sure to fix them.

FacebookTwitterLinkedinLinkedin
knowledge base

Vector Bases