R Functions S&DS Exam One

abline()

Adds a straight line to a plot.

abs()

Returns the absolute value of a number.

apply()

Applies a function to rows or columns of a matrix or array.

as.character()

Converts an object to a character (text) type.

as.numeric()

Converts an object to a numeric type.

as.vector()

Converts an object to a vector.

attach()

Attaches a dataset to the search path, making its columns accessible by name.

barplot()

Creates a bar chart.

boot()

Performs bootstrapping (resampling) for statistical analysis.

boot.ci()

Calculates confidence intervals for bootstrapped results.

boxplot()

Creates a boxplot to visualize data distribution.

by()

Applies a function to subsets of data based on a factor.

c()

Combines values into a vector or list.

calcTemp()

(Custom function) Likely calculates temperature-related values.

cbind()

Combines columns into a matrix or data frame.

cex()

Controls the size of text and symbols in plots.

class()

Returns the class (type) of an object.

cleanNHData()

(Custom function) Likely cleans or preprocesses NH (New Hampshire) data.

colnames()

Gets or sets the column names of a matrix or data frame.

colors()

Lists available color names in R.

colSums()

Calculates the sum of each column in a matrix or data frame.

complete.cases()

Identifies rows with no missing values.

convertTimes()

(Custom function) Likely converts time formats.

data.frame()

Creates a data frame (a table-like structure).

dbinom()

Calculates the probability density for a binomial distribution.

demo()

Runs demonstration scripts in R.

dexp()

Calculates the probability density for an exponential distribution.

dim()

Returns the dimensions (rows and columns) of a matrix or data frame.

dirname()

Extracts the directory name from a file path.

dnorm()

Calculates the probability density for a normal distribution.

droplevels()

Removes unused levels from a factor.

duplicated()

Identifies duplicate rows or elements.

exp()

Calculates the exponential value of a number.

factor()

Converts a vector into a factor (categorical variable).

for()

Creates a loop to repeat a task multiple times.

function()

Defines a custom function in R.

getwd()

Returns the current working directory.

glm()

Fits a generalized linear model.

gsub()

Replaces text patterns in a string.

head()

Displays the first few rows of a dataset.

help()

Opens documentation for a function.

hist()

Creates a histogram to show data distribution.

hms()

(Custom function) Likely handles time in hours, minutes, and seconds.

install.packages()

Installs R packages from CRAN.

intersect()

Finds common elements between two vectors.

is.na()

Checks for missing values (NA) in data.

las()

Controls the orientation of axis labels in plots.

legend()

Adds a legend to a plot.

length()

Returns the number of elements in a vector or list.

levels()

Gets or sets the levels of a factor.

library()

Loads an R package.

lines()

Adds lines to a plot.

list()

Creates a list (a collection of objects).

lm()

Fits a linear regression model.

ln()

(Custom function) Likely calculates the natural logarithm.

log()

Calculates the natural logarithm.

log10()

Calculates the base-10 logarithm.

ls()

Lists all objects in the current environment.

matrix()

Creates a matrix.

mean()

Calculates the average of a set of numbers.

median()

Calculates the middle value of a set of numbers.

merge()

Combines two datasets into one.

mosaicplot()

Creates a mosaic plot for categorical data.

ms()

(Custom function) Likely handles time in milliseconds.

mtext()

Adds text to the margins of a plot.

n()

(Custom function) Likely counts the number of rows or elements.

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na.omit()

Removes rows with missing values.

names()

Gets or sets the names of an object.

nchar()

Returns the number of characters in a string.

options()

Sets or retrieves global R options.

par()

Sets graphical parameters for plots.

paste()

Combines strings with a separator.

paste0()

Combines strings without a separator.

plot()

Creates a basic graph or scatter plot.

points()

Adds points to a plot.

Points()

(Custom function) Likely adds points to a plot.

print()

Displays an object in the console.

punctuation()

(Custom function) Likely handles punctuation in text.

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qqline()

Adds a reference line to a Q-Q plot.

qqnorm()

Creates a Q-Q plot for normality testing.

qqPlot()

Creates a Q-Q plot with additional features.

quantile()

Calculates quantiles of a dataset.

range()

Returns the minimum and maximum values of a dataset.

rbinom()

Generates random numbers from a binomial distribution.

read.csv()

Reads data from a CSV file into R.

read.data()

(Custom function) Likely reads data from a file.

rep()

Repeats a value or vector multiple times.

return()

Specifies the output of a function.

rexp()

Generates random numbers from an exponential distribution.

rm()

Removes objects from the environment.

rnorm()

Generates random numbers from a normal distribution.

round()

Rounds numbers to a specified number of decimal places.

rownames()

Gets or sets the row names of a matrix or data frame.

runif()

Generates random numbers from a uniform distribution.

sample()

Randomly samples elements from a vector.

sd()

Calculates the standard deviation of a dataset.

seq()

Generates a sequence of numbers.

set.seed()

Sets the random number generator seed for reproducibility.