Data Structure

Data Structure - Matrix

Q

What is a Matrix?

✍: FYIcenter.com

A

Matrix is an extension of vector into 2 dimensions

1. Create a matrix object with the matrix() function -

> m = matrix(1:20, nrow=5,ncol=4)
> m
     [,1] [,2] [,3] [,4]
[1,]    1    6   11   16
[2,]    2    7   12   17
[3,]    3    8   13   18
[4,]    4    9   14   19
[5,]    5   10   15   20

> typeof(m)
[1] "integer"

> is.matrix(m)
[1] TRUE

> is.vector(m)
[1] FALSE

2. Get matrix length, dimensions and members -

> m = matrix(1:20, nrow=5,ncol=4)

> length(m)
[1] 20

> dim(m)
[1] 5 4

> m[3,2]
[1] 8

⇒ Data Structure - Data Frame

⇐ Data Structure - Factor

⇑ R Language Basics

⇑⇑ R Software Environment - Frequently Asked Questions

2023-05-31, ∼1386🔥, 0💬

Data Structure - Named Vector
What is a named vector? A named vector is a special vector where each member has a unique name. A name vector is an associated array in many other programming language. 1. Create a named vector object with the name() function - > v = c("Apple", "Banana", "Orange") > v [1] "Apple" "Bana... 2023-06-11, ∼1427🔥, 0💬

Data Structure - List
What is data structure "List"? List is a special vector whose members are all lists. 1. Create a list object with the list() function - > w = list( c(1,2,3), c("Apple", "Banana", "Orange")) > w [[1]] [1] 1 2 3 [[2]] [1] "Apple" "Banana" "Orange" > is.list(w) [1] TRUE > is... 2023-06-11, ∼1408🔥, 0💬

Data Structure - Matrix
What is a Matrix? Matrix is an extension of vector into 2 dimensions 1. Create a matrix object with the matrix() function - > m = matrix(1:20, nrow=5,ncol=4) > m [,1] [,2] [,3] [,4] [1,] 1 6 11 16 [2,] 2 7 12 17 [3,] 3 8 13 18 [4,] 4 9 14 19 [5,] 5 10 15 20 > typeof(m) [1] "inte... 2023-05-31, ∼1387🔥, 0💬

Data Frame Example - "cars"
What is the Data Frame Example, "cars"? "cars" is a built-in data frame example in R environment. "cars" has two columns: "speed" and "dist". Each row records an instance of the stopping distance of a car driving at a given speed. Note that the data were recorded in the 1920s. 1. Basic info on "cars... 2023-05-31, ∼1356🔥, 0💬

Data Structure - Factor
What is a Factor? A factor is a data structure that stores a vector and its distinct values as categories. 1. Create a factor object with the factor() function - > f = factor( c("Bike", "Car", "Truck", "Car", "Bike", "Truck") ) > f [1] Bike Car Truck Car Bike Truck Levels: Bike Car Tru... 2023-05-31, ∼1347🔥, 0💬

The R Graphics Package
What is The R Graphics Package? The R Graphics Package is built-in "graphics" package in the R environment. It provides functions for "base" graphics, which are traditional S-like graphics, as opposed to the more recent grid graphics. Here is a list of all functions provided in "graphics 4.0.5" rele... 2023-05-09, ∼1340🔥, 0💬

Vector Is Not a Data Type
Is Vector a Data Type? No. Technically, "Vector" is not a data type. In R, all data items are technically "vectors". In other words, everything is a vector in R. There is no "scalar" data. This is why data "3" is printed out as "[1] 3" on the console, indicating that "3" is a vector of 1 member: &am... 2023-06-11, ∼1328🔥, 0💬

Data Structure - Data Frame
What is a Data Frame? Data Frame is a generalization of matrix where columns may have different data types. Technically, a data frame is a special list. 1. Create a factor object with the data.frame() function - > name = c("Lori", "Mike", "Nill", "Sofi") > sex = factor( c("F", "M", "M"... 2023-05-31, ∼1253🔥, 0💬

Get Help in R Environment
How to get help in R environment? You can use the help() function to get help in R environment. 1. Get help on the help() function: > help(help) help is the primary interface to the help systems. Usage help(topic, package = NULL, lib.loc = NULL, verbose = getOption("verbose"), try.all.package... 2023-05-31, ∼1140🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.