R Programming Basics and Data Structures

A comprehensive set of vocabulary flashcards covering R programming basics, including mathematical and logical operators, data types, data structures, control flow (loops and conditionals), and the apply family of functions.

seq()

A function used to define numeric sequences using arguments such as from, to, and by.

%/%

The mathematical operator for integer division.

%%

The mathematical operator for modulo (remainder) division.

NaN

An indicator representing an undefined value or 'Not a Number.'

NA

An indicator representing a missing value.

NULL

An indicator representing an empty set or object.

%*%

The mathematical operator used for matrix multiplication.

xor()

A logical function representing the 'exclusive or' operation.

&& and ||

Logical operators that can only be used to compare inputs of length $1$.

& and |

Logical operators used to compare elements of two vectors component-wisely.

typeof()

A function used to check the internal data type of an object.

logical

A data type representing Boolean values: TRUE and FALSE.

character

A data type used for character strings, such as "text".

factor

A data type used for texts, strings, or numbers that represent categories.

integer

A data type specifically for whole numbers, such as $3$.

double (numeric)

A data type for integers or real numbers, such as $-2 \times \exp(1)$.

complex

A data type for complex numbers, such as $2 - 1i$.

as.character()

A function used to convert an object to a character data type.

Vector

A basic data structure in R that does not allow mixing of different data types.

rep()

A function used to replicate elements of vectors, including arguments for 'times' and 'each'.

matrix()

A function used to define a matrix, with options for nrow, ncol, and byrow.

cbind()

A function used to combine objects by columns.

rbind()

A function used to combine objects by rows.

dim()

A function that returns the dimensions (number of rows and columns) of a matrix or data frame.

solve(X)

A function used to calculate the inverse of a matrix $X$.

t(X)

A function used to calculate the transpose of a matrix $X$.

array()

A data structure that can contain an arbitrary number of dimensions.

list()

A flexible data structure that can contain elements of different data types and structures.

data.frame

The central data structure for data sets, consisting of a list of vectors of the same length.

str()

A function that returns the internal structure of a data object.

subset()

A function used to create a subset of a data frame based on logical conditions.

identical()

A function used to check whether two objects are exactly equal.

order()

A function that returns a permutation to rearrange an argument into ascending or descending order.

any()

A logical operation that returns TRUE if at least one component of a logical vector is TRUE.

all()

A logical operation that returns TRUE if all components of a logical vector are TRUE.

which()

A function that returns the indices of each component where a logical condition is TRUE.

function()

The keyword used to define a custom function with specified parameters.

return()

A statement used to explicitly specify the value that a function should return.

… (dots)

An argument used in function definitions to allow an unspecified number of expected arguments.

if … else

A conditional statement used to execute specific command sequences based on a logical condition.

ifelse()

A vectorized version of the if-else statement used for vector-valued evaluation of conditions.

for loop

A loop structure used to repeat commands when the exact number of iterations is known.

while loop

A loop structure used to repeat operations as long as a specific condition remains TRUE.

repeat loop

A loop structure that repeats an instruction sequence until a break condition is encountered.

apply()

A function that applies another function to the margins (rows or columns) of an array or matrix.

lapply()

A function that applies another function component-wise to a list, data set, or vector and returns a list.

sapply()

A function that behaves like lapply() but returns the output as a vector or a matrix.

tapply()

A function that applies another function to each group of values defined by unique factor levels.