# Terminology

Vector

A list of numbers (or characters). Has dimensions, which you can get using the size command (e.g. size(A)). Can either be a row vector, with dimensions of (1,n) or a column vector, with dimensions of (n,1).

Matrix

A 2-dimensional array of numbers. Has dimensions which you can get using the size command, but will have a size of (m,n) where both m and n are greater than one.

Command / function

An set of instructions that you can run. Examples of commands (or functions): help, plot, length, mean. Functions have the ability take in a number of arguments (see below)

Argument

What we call the inputs to a command or function. For example, calling the function plot(x,y) means that you passed in two arguments, x and y.

## Element-wise operations

For arithmetic operations (multiplication and division), Matlab defaults to using matrix operations. For example, if you have two arrays x and y, and try to run x*y, Matlab will try to compute the dot product between the arrays (if you aren't familiar with this, don't worry about it, it is from linear algebra).

Instead, we often want to compute what is called element-wise operations, that is, multiply (or divide) the individual elements in a pair of arrays or matrices. To do this, place a dot (.) before the corresponding operation. This gives us dot-multiply (.*) and dot-division (./).