Commands
|
Purpose
|
help() | Obtain documentation for a given R command |
example() | View some examples on the use of a command |
c(), scan() | Enter data manually to a vector in R |
seq() | Make arithmetic progression vector |
rep() | Make vector of repeated values |
data() | Load (often into a data.frame) built-in dataset |
View() | View dataset in a spreadsheet-type format |
str() | Display internal structure of an R object |
read.csv(), read.table() | Load into a data.frame an existing data file |
library(), require() | Make available an R add-on package |
dim() | See dimensions (# of rows/cols) of data.frame |
length() | Give length of a vector |
ls() | Lists memory contents |
rm() | Removes an item from memory |
names() | Lists names of variables in a data.frame |
hist() | Command for producing a histogram |
histogram() | Lattice command for producing a histogram |
stem() | Make a stem plot |
table() | List all values of a variable with frequencies |
xtabs() | Cross-tabulation tables using formulas |
mosaicplot() | Make a mosaic plot |
cut() | Groups values of a variable into larger bins |
mean(), median() | Identify “center” of distribution |
by() | apply function to a column split by factors |
summary() | Display 5-number summary and mean |
var(), sd() | Find variance, sd of values in vector |
sum() | Add up all values in a vector |
quantile() | Find the position of a quantile in a dataset |
barplot() | Produces a bar graph |
barchart() | Lattice command for producing bar graphs |
boxplot() | Produces a boxplot |
bwplot() | Lattice command for producing boxplots |
help() | Obtain documentation for a given R command |
example() | View some examples on the use of a command |
c(), scan() | Enter data manually to a vector in R |
seq() | Make arithmetic progression vector |
rep() | Make vector of repeated values |
data() | Load (often into a data.frame) built-in dataset |
View() | View dataset in a spreadsheet-type format |
str() | Display internal structure of an R object |
read.csv(), read.table() | Load into a data.frame an existing data file |
library(), require() | Make available an R add-on package |
dim() | See dimensions (# of rows/cols) of data.frame |
length() | Give length of a vector |
ls() | Lists memory contents |
rm() | Removes an item from memory |
names() | Lists names of variables in a data.frame |
hist() | Command for producing a histogram |
histogram() | Lattice command for producing a histogram |
stem() | Make a stem plot |
table() | List all values of a variable with frequencies |
xtabs() | Cross-tabulation tables using formulas |
mosaicplot() | Make a mosaic plot |
cut() | Groups values of a variable into larger bins |
mean(), median() | Identify “center” of distribution |
by() | apply function to a column split by factors |
summary() | Display 5-number summary and mean |
var(), sd() | Find variance, sd of values in vector |
sum() | Add up all values in a vector |
quantile() | Find the position of a quantile in a dataset |
barplot() | Produces a bar graph |
barchart() | Lattice command for producing bar graphs |
boxplot() | Produces a boxplot |
bwplot() | Lattice command for producing boxplots |
plot() | Produces a scatterplot |
xyplot() | Lattice command for producing a scatterplot |
lm() | Determine the least-squares regression line |
anova() | Analysis of variance (can use on results of lm()) |
predict() | Obtain predicted values from linear model |
nls() | estimate parameters of a nonlinear model |
residuals() | gives (observed - predicted) for a model fit to data |
sample() | take a sample from a vector of data |
replicate() | repeat some process a set number of times |
cumsum() | produce running total of values for input vector |
ecdf() | builds empirical cumulative distribution function |
dbinom(), etc. | tools for binomial distributions |
dpois(), etc. | tools for Poisson distributions |
pnorm(), etc. | tools for normal distributions |
qt(), etc. | tools for student t distributions |
pchisq(), etc. | tools for chi-square distributions |
binom.test() | hypothesis test and confidence interval for 1 proportion |
prop.test() | inference for 1 proportion using normal approx. |
chisq.test() | carries out a chi-square test |
fisher.test() | Fisher test for contingency table |
t.test() | student t test for inference on population mean |
qqnorm(), qqline() | tools for checking normality |
addmargins() | adds marginal sums to an existing table |
prop.table() | compute proportions from a contingency table |
par() | query and edit graphical settings |
power.t.test() | power calculations for 1- and 2-sample t |
anova() | compute analysis of variance table for fitted model |