R Functions

Question 1

abline()

Answer 1

Adds straight line to a plot. v = “” puts a vertical line at corresponding to a specific coordinate.

Question 2

abs()

Answer 2

Absolute value

Question 3

apply()

Answer 3

apply(x, margin, fun)
x = dataframe, matrix, etc.
margin = parameter
fun = function to apply to data

Question 4

as.character()

Answer 4

convert to character vectors

Question 5

as.numeric

Answer 5

converts data to numeric values

Question 6

as.vector

Answer 6

converts data to a vector (returns r vector)

Question 7

attach()

Answer 7

turns all variables in dataframe into their own objects

Question 8

barplot()

Answer 8

creates a barplot

Question 9

boot()

Answer 9

IDK

Question 10

boot.ci()

Answer 10

IDK

Question 11

boxplot()

Answer 11

creates a boxplot

Question 12

by()

Answer 12

localized function. allows us to apply a function toa certain subsect of a data frame
by(data, indices, fun)
data = dataframe, vector, etc.
indices: defines data points that will be split into certain subsets
fun: function that will act on component
AKA by() performs FUN on DATA for each INDICE

Question 13

c()

Answer 13

concatanate. combines things into a vector

Question 14

calcTemp()

Answer 14

IDK

Question 15

cbind()

Answer 15

combines multiple vectors (or matrices or dataframes) by their columns

Question 16

cex()

Answer 16

allows u to change size of characters

Question 17

class()

Answer 17

IDK

Question 18

cleanNHdata

Answer 18

IDK // i mean i kinda do know but is this a real fx they would want us to use…

Question 19

colnames()

Answer 19

returns OR sets the names of columns
to set names of columns:
colnames(df) <- c(“x”, “y”, “z”)

Question 20

colors()

Answer 20

specifies color (usually in a plot of some sort)

Question 21

colSums()

Answer 21

IDK/come back

Question 22

complete.cases()

Answer 22

IDK/come back

Question 23

convertTimes()

Answer 23

IDK/come back

Question 24

data.frame()

Answer 24

turns something into a data frame? IDK/come back

Question 25

dbinom()

Answer 25

IDK/come back

Question 26

demo()

Question 27

dexp()

Question 28

dim()

Answer 28

Gives the dimensions of a dataset (amount of rows and columns)

Question 29

dirname()

Question 30

dnorm()

Question 31

droplevels()

Answer 31

remove old/previous factor levels

Question 32

duplicated()

Answer 32

determines which elements of a dataset are duplicates --> returns a true/false vector

Question 33

exp()

Answer 33

calculates the power of e for whatever the input is. as in e ^ input

Question 34

factor()

Answer 34

encodes a vector as a factor (turns a column from numeric to factor).

Question 35

for()

Answer 35

creates a for loop. syntax: for(variable in vector) {statement(s) } * i is generic variable

Question 36

function()

Answer 36

creates a function. syntax function() { print("something") }

Question 37

glm()

Answer 37

irrelevant

Question 38

gsub()

Answer 38

finds and deletes segments. gsub(what to replace, "replacement", dataframe)

Question 39

head()

Question 40

help()

Question 41

hist()

Question 42

hms()

Question 43

install.packages()

Question 44

intersect()

Question 45

is.na()

Answer 45

if set to false, removes na values

Question 46

las()

Answer 46

makes labels horizontal or parallel to axis. las = 0 is parallel, las = 2 is perpendicualr (0 is the default)

Question 47

legend()

Answer 47

adds legend to plot. legend(topright, etc.)

Question 48

length()

Answer 48

gets the length of vectors or lists

Question 49

levels()

Answer 49

allows us to assign (or see) levels to a variable. levels(x) = c("low", "high")

Question 50

library()

Question 51

lines()

Question 52

list()

Answer 52

creates a list of things (string, numbers, etc.)

Question 53

ln()

Answer 53

finds the natural log of smt

Question 53

lm()

Question 54

log()

Answer 54

find the natural log of smth

Question 55

log10()

Answer 55

find base 10 logarithm of smth

Question 56

ls()

Answer 56

see list of all objects in workspace

Question 57

matrix()

Answer 57

creates a matrix. matrix(data, nrow = 1, ncol = 1, byrow = TRUE)

Question 58

mean()

Answer 58

mean

Question 59

median()

Answer 59

median

Question 60

merge()

Answer 60

merges dataframes or columns merge( x, y, by = x)

Question 61

mosaicplot()

Question 62

N()

Question 62

ms()

Answer 62

turns character or numeric vectors into object with numbers of minutes and seconds

Question 62

mtext()

Answer 62

allows to write text in the margins of a plot mtext(text, side=3, line =0)

Question 63

n()

Answer 63

gives the number of observations in a group

Question 64

na.omit()

Answer 64

allows us to omit missing values in objects na.omit(object)

Question 65

names()

Answer 65

gives the names of an object

Question 65

nchar()

Answer 65

counts the number of characters

Question 66

par()

Answer 66

sets graphical parameters. par(mfrow = c(1,2))

Question 66

paste0()

Question 67

paste()

Answer 67

Takes multiple elements from multiple vectors and concatenates them into one element. paste(1, 2, 3, sep = "and")

Question 68

plot()

Answer 68

generic function for plotting objects plot(x, y) * y optional if x appropriate structure

Question 69

points()

Question 70

Points()

Question 71

qq_Plot()

Question 72

punctuation()

Question 72

print()

Question 73

qqnorm()

Question 74

qqline()

Question 74

qqPlot()

Answer 74

creates a normal quantile plot based on a data set

Question 75

quantile()

Question 76

read.csv()

Question 76

range()

Question 76

rbinom()

Question 77

read.data()

Question 78

rexp()

Question 78

rep()

Question 79

return()

Question 80

rnorm()

Question 80

rownames()

Question 81

rm()

Question 82

round()

Question 83

sample()

Question 83

seq()

Question 84

runif()

Question 85

sd()

Question 86

setwd()

Question 87

set.seed()

Question 88

sort()

Question 89

str()

Question 90

sqrt()

Question 91

subset()

Question 92

substr()

Question 93

summary()

Question 93

t.test()

Question 94

sum()

Question 95

t()

Question 96

table()

Question 97

text()

Question 98

tail()

Question 99

tolower()

Question 100

toTitleCase()

Question 101

unique()

Question 101

trimws()

Question 102

var()

Question 103

which()

Question 104

write.csv()