DataFormats.R

# File:   DataFormats.R
# Course: R: An Introduction (with RStudio)

# DATA TYPES ###############################################

# Numeric

n1 <- 15  # Double precision by default
n1
typeof(n1)

n2 <- 1.5
n2
typeof(n2)

# Character

c1 <- "c"
c1
typeof(c1)

c2 <- "a string of text"
c2
typeof(c2)

# Logical

l1 <- TRUE
l1
typeof(l1)

l2 <- F
l2
typeof(l2)

# DATA STRUCTURES ##########################################

## Vector ##################################################

v1 <- c(1, 2, 3, 4, 5)
v1
is.vector(v1)

v2 <- c("a", "b", "c")
v2
is.vector(v2)

v3 <- c(TRUE, TRUE, FALSE, FALSE, TRUE)
v3
is.vector(v3)

## Matrix ##################################################

m1 <- matrix(c(T, T, F, F, T, F), nrow = 2)
m1

m2 <- matrix(c("a", "b", 
               "c", "d"), 
               nrow = 2,
               byrow = T)
m2

## Array ###################################################

# Give data, then dimemensions (rows, columns, tables)
a1 <- array(c( 1:24), c(4, 3, 2))
a1

## Data frame ##############################################

# Can combine vectors of the same length

vNumeric   <- c(1, 2, 3)
vCharacter <- c("a", "b", "c")
vLogical   <- c(T, F, T)

dfa <- cbind(vNumeric, vCharacter, vLogical)
dfa  # Matrix of one data type

df <- as.data.frame(cbind(vNumeric, vCharacter, vLogical))
df  # Makes a data frame with three different data types

## List ####################################################

o1 <- c(1, 2, 3)
o2 <- c("a", "b", "c", "d")
o3 <- c(T, F, T, T, F)

list1 <- list(o1, o2, o3)
list1

list2 <- list(o1, o2, o3, list1)  # Lists within lists!
list2

# COERCING TYPES ###########################################

## Automatic coercion ######################################

# Goes to "least restrictive" data type

(coerce1 <- c(1, "b", TRUE))
# coerce1  # Parenthese around command above make this moot
typeof(coerce1)

## Coerce numeric to integer ###############################

(coerce2 <- 5)
typeof(coerce2)

(coerce3 <- as.integer(5))
typeof(coerce3)

## Coerce character to numeric #############################

(coerce4 <- c("1", "2", "3"))
typeof(coerce4)

(coerce5 <- as.numeric(c("1", "2", "3")))
typeof(coerce5)

## Coerce matrix to data frame #############################

(coerce6 <- matrix(1:9, nrow= 3))
is.matrix(coerce6)

(coerce7 <- as.data.frame(matrix(1:9, nrow= 3)))
is.data.frame(coerce7)

# CLEAN UP #################################################

# Clear environment
rm(list = ls()) 

# Clear console
cat("\014")  # ctrl+L

# Clear mind :)