Basic symbols and terminology
In the following section, we will review the mathematical concepts of vectors, matrices, arithmetic symbols, and linear algebra, as well as some more subtle notations that are used by data scientists.
Vectors and matrices
A vector is defined as an object with both magnitude and direction. This definition, however, is a bit complicated. For our purpose, a vector is simply a 1-dimensional array representing a series of numbers. Put another way, a vector is a list of numbers.
It is generally represented using an arrow or bold font, as follows:
Vectors are broken into components, which are individual members of the vector. We use index notations to denote the element that we are referring to, as follows:
Note
In math, we generally refer to the first element as index 1, as opposed to computer science, where we generally refer to the first element as index 0. It is important to remember which index system you are using.
In Python, we can represent arrays in many ways. We...
