Descriptive Statistics - Agricultural Statistical Data Analysis Using Stata - page 55

3
D eScriPtive S tatiSticS
Before beginning, it might be a good idea to start a log of the session.
This way all of your calculations are saved for future reference and use.
I make a lot of mistakes when working with a dataset and sometimes
I discover something new with the program. Having a log makes it
easy to go back and see what was done and pull out information as I
write reports and papers.
At this point, I will not be describing the menu location for a
specific command, nor will there be illustrations of every command
dialog window. Having read through Chapter 2, you should have a
good idea how these work. If you want to know where a particular
menu item is located, type help and the specific command in the
Command region of the main menu or in a Viewer window and the
Help file will list where a particular menu can be found.
After opening a dataset and manipulating the data and variables
for analysis, one of the most useful commands is describe . This
will give you an overview of what the dataset consists of. The com-
mand can be used on a dataset in memory or on disk. The formats for
this command are
describe [ varlist ] [, memory_options ]
describe [ varlist ] using filename [, file_options ]
he describe command gives you information about how many
observations are in the dataset, the number of variables, the storage
type, display format, if there are value labels, and variable labels. If
there is a dataset label, this also will be displayed.
If you have any familiarity with computers and programming, the
storage type will be familiar to you. Different types of data take up
different amounts of memory. For example, a byte is used for dig-
its without decimal places, but has a small range of allowed val-
ues (-127 to 100), whereas variables stored as float have decimals
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