Glossary
abline() - A generic function adds one or more straight lines through the current plot.
AIC() - A generic function computing Akaike's ‘An Information Criterion’ for one or several fitted model objects.
anova() - A generic function that computes an analysis of the variance.
arrows() - A function that draws an arrow between a pairs of points.
barplot() - Computes a bar plot of the given values.
c() - A function that concatenates objects into a vector.
colnames() - Retrieves or sets the row or column names of a matrix-like object.
Comment - A line beginning with a hash, that contains a description or explanation of how the commands operate.
cor() - Computes the variance of the values in the specified vector.
cov() - Computes the covariance of x and y if these are vectors. If x and y are matrices then the covariances between the columns of x and the columns of y are computed.
data() - Displays the list of pre-defined data sets available within R.
Data Frame - An object construct used for storing tabular data.
edit() - Opens a data editor to allow editing of a data frame or matrix.
Equation - An equation shows the mathematical relationship between a group of variables.
factor() - A function which stores a vector of integer values with a corresponding set of character values to use when the factor is displayed. Factors are variables which take on a limited number of different values; such variables are often referred to as categorical variables.
formula() - A generic function and its specific methods that provide a way of extracting formulae which have been included in other objects.
Function - A method that describes the relationship between the result generated from performing various operations on a group of variables.
getwd() - Displays the current working directory.
gl() - A function to generate factors by specifying the pattern of their levels.
help() - Displays the help information.
hist() - Computes a histogram of the given values.
length() - Displays the number of elements in a vector or list.
list() - A generic vector that can contain objects of differing types. Often referred to as a record in other programming languages.
lm() - A generic function that computes the best fit of linear models. It can be used to carry out regression, single stratum analysis of variance and analysis of covariance.
mean() - A generic function that computes the arithmetic mean.
methods() - Displays the list of associated functions that belong to an object.
NA - Not Applicable.
Object - A generic term that describes something (an object) which contains related information.
par() - Retrieves or sets the graphical parameters.
plot() - Plots the specified function in the graphics window.
points() - A generic function to draw a sequence of points at the specified coordinates. The specified character(s) are plotted, centered at the coordinates.
predictor - A variable that can be used to predict the outcome value of another variable (as in statistical regression).
R Console - A window that acts as a console terminal to allow the user to interact with R.
R Editor - A window that displays an editable spreadsheet to allow the user to edit data values.
R Graphics - A window that displays the output from graphical commands.
rank() - Returns the sample ranks of the values in a vector.
read() - A generic function for reading in input files.
residuals() - Computes the residuals of a linear model.
rev() - Provides a reversed version of the object.
Script - A series of commands that are stored in a file, for easy access and re-use.
setwd() - Sets the current working directory.
sort() - Sorts a vector or factor into ascending or descending order.
str() - Compactly displays the internal structure of an R object.
sum() - Returns the sum of all of the elements in a vector.
summary - A generic function used to produce result summaries of the results of various model fitting functions.
text() - A generic function that draws the text string given in the vector labels at the coordinates given by x and y.
Variable - A variable is an object that contains either numeric or character data representing the values associated with an object.
Vector - A programming construct that defines a collection of variables of the same type. Often referred to as an array in other programming languages.
which() - Give the TRUE indices of a logical object, allowing for array indices.