Kaarten: stat 3 operators & functions | Quizlet

!

not

|

or

&

and

%in%

Equivalent to == . To select from a list, where telling if the elements are true or not with logical values

class()

function which shows the classification of data

mode()

function which shows how the data is used

exp()

exponentiation of e to a certain number

cumsum()

gives the cfreq

head() / tail()

gives the last or first 6 (by default) elements from the variable. n can be specified

which()

shows element number about what you specify ex. function(sales>100) gives sales above 100

recylcing rule

2 vectors with a different length, one of them will be repeating the command over the other one. this can only be done when they are the same length when repeated

floating point arithmetic

Performing simple calculations on more than one floating-point number stored in binary notation. this results in a rounding error

all.equal()

solution for floating-point arithmetic.

objects() / ls()

gives all stored variable names stored in global environment

ls.str()

Shows variables in memory, which kind of variables they are and their types

Inf

when something has an infinite value

NaN

not a number

NA

not available

NULL

no value

rbind()

creating a matrix by rows

cbind()

creating a matrix by columns

t()

transposing, turning a matrix the other way

as.factor()

converts data to factor data. Is useful for nominal data & makes levels out of the elements

$

for refering to a certain variable in a data frame

barplot()

staafdiagram

sapply()

implicit loop where FUN should be specified and X= . FUN will hold a certain function it applies to X

tapply()

implicit loop where INDEX holds a grouping variable. (ex. gender) over this grouping variable there will be a function applied where specified at FUN

by()

implicit loop where INDEX holds a grouping variable. (ex. gender) over this grouping variable there will be a function applied where specified at FUN

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