Appendix D - Most essential R commands
- Page ID
- 3623
This is the short collection of the most frequently used R commands based on the analysis of almost 500 scripts (Figure 3.4.2). For the longer list, check R reference card attached to this book, or R help and manuals.
- ?
-
Help
- <-
-
Assign right to left
- [
-
Select part of object
- $
-
Call list element by name
- abline()
-
Add the line from linear regression model
- aov()
-
Analysis of variation
- as.character()
-
Convert to text
- as.numeric()
-
Convert to number
- as.matrix()
-
Convert to matrix
- boxplot()
-
Boxplot
- c()
-
Join into vector
- cbind()
-
Join columns into matrix
- chisq.test()
-
Chi-squared test
- cor()
-
Correlation of multiple variables
- colSums()
-
Sum every column
- cor.test()
-
Correlation test
- data.frame()
-
Make data frame
- dev.off()
-
Close current graphic device
- dotchart()
-
Replacement for “pie” chart
- example()
-
Call example of command
- factor()
-
Convert to factor, modify factor
- file.show()
-
Show file from disk
- function() ...
-
Make new function
- head()
-
Show first rows of data frame
- help()
-
Help
- hist()
-
Histogram
- ifelse()
-
Vectorized condition
- legend()
-
Add legend to the plot
- library()
-
Load the installed package
- length()
-
Length (number of items) of variable
- list()
-
Make list object
- lines()
-
Add lines to the plot
- lm()
-
Linear model
- log()
-
Natural logarithm
- log10()
-
Decimal logarithm
- max()
-
Maximal value
- mean()
-
Mean
- median()
-
Median
- min()
-
Minimal value
- NA
-
Missed value
- na.omit
-
Skip missing values
- names()
-
Show names of elements
- nrow()
-
How many rows?
- order()
-
Create order of objects
- paste()
-
Concatenate two strings
- par()
-
Set graphic parameters
- pdf()
-
Open PDF device
- plot()
-
Graph
- points()
-
Add points (dots) to the plot
- predict()
-
Predict values
- q("no")
-
Quit R and do not save workspace
- qqnorm(); qqline()
-
Visual check for the normality
- rbind()
-
Join into matrix by rows
- read.table()
-
Read data file from disk into R
- rep()
-
Repeat
- sample()
-
Random selection
- savehistory()
-
Save history of commands (does not work under macOS GUI)
- scale()
-
Make all variables comparable
- sd()
-
Standard deviation
- source()
-
Run script
- str()
-
Structure of object
- summary()
-
Explain the object, e.g., return main description statistics
- t()
-
Transpose matrix (rotate on right angle)
- t.test()
-
Student test (t-test)
- table()
-
Make contingency table
- text()
-
Add text to the plot
- url.show()
-
Show the Internet file
- wilcox.test()
-
Wilcoxon test
- write.table()
-
Write to disk