Some Basic Tips

R code can be entered into the command line directly or saved to a script, which can be run inside a session using the source function
Commands are separated either by a ; or by a newline.
R is case sensitive.
The # character at the beginning of a line signifies a comment, which is not executed.

R stores both data and output from data analysis (as well as everything else) in objects
Things are assigned to and stored in objects using the <- or = operator
A list of all objects in the current session can be obtained with ls()

Dataset Files

R works most easily with datasets stored as text files. Typically, values in text files are separated, or delimited, by tabs or spaces:

gender id race ses schtyp prgtype read write math science socst

0 70 4 1 1 general 57 52 41 47 57

1 121 4 2 1 vocati 68 59 53 63 31

0 86 4 3 1 general 44 33 54 58 31

0 141 4 3 1 vocati 63 44 47 53 56

gender,id,race,ses,schtyp,prgtype,read,write,math,science,socst

0,70,4,1,1,general,57,52,41,47,57

1,121,4,2,1,vocati,68,59,53,63,61

0,86,4,3,1,general,44,33,54,58,31

0,141,4,3,1,vocati,63,44,47,53,56

Using > dim(dataset name), we get the dimensions of the dataset, i.e., the number of observations(rows) and variables(columns)

Using > str(dataset name), we get the structure of the dataset, including the class(type) of all variables