Data analytics test 1

What is a variable?

A named storage which can be manipulated by the program, example X=5

Elementary (aka atomic aka primitive) data types

They are predefined and represent single values and are typically stored in memory.

Vector variables

normally contain more than just one value, can be created in the program using a function c(), the combine function. Ex: X= c(2,4,6) creates a vector variable X, consisting of three values. All elements of a vector variable must have the same elementary data type. Vectors can be used to store data about a certain attribute

CART nodes root, internal, terminal

Root node (top): full dataset. Internal/decision nodes (middle): decision rules that split data. Terminal nodes / leaves (bottom): final classification or outcome.