Mode and Vector
Quantitative Trading
Online Flipped Classroom
English Medium Instruction
Jen-We Yang
Introduction to mode and vector
Mode describes the data type.
Vector is the most basic object in R language.
 Other objects, such as matrix and data frame, are constructed
from vector object.
 Vector and mode are very, very, very important.
 It is necessary to lay a good foundation of vector &
mode for learning other objects efficiently.
What is data type & mode?
Example or explanation
Data type
mode (x)
1. Numeric (real) number
numeric
EX: 2, 0.5, -15
2. Complex number
complex
3. Character
character
EX: 3+4i, -2i, 1i
 In computer science, a character is a unit of information
corresponding to a grapheme or symbol, such as letters,
numerical numbers, punctuation marks, whitespace, and so on.
4. Logic
5. Missing value
 In R, any mode between two double quotation marks is
Character.
EX: "Who are you? ", "嗨", "3+1=4", "TRUE", "F", "NA", "NaN".
logical
True (T) or False (F)
numeric
NaN (Not a Number)
logical
NA (No available)
Rules for modes on a vector
 Missing values can be mixed with other modes in a vector.
 If you input different models into a vector, R language will transform
them to the same model according to the transform order.
Priority
Mode(x)
1
2
character complex
3
4
numeric
logical
Given a vector x, but we don't know its elements.
Mode(x)
Elements of x
Logical numeric
complex
T;F
NA
T;F
NA
Numeric
NaN
Complex
T;F
NA
Numeric
NaN
character
T;F
NA
Numeric
NaN
Complex
Character
How to identify T , F, NA, Real number, NaN, Complex, Character?