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Stata Class Notes
Creating Your Own Datasets

1.0 Stata commands in this unit

By now you know that we will not be showing all of the options for any of the commands.

. clear
edit
save
infile
insheet

2.0 Demonstration and Explanation

. clear

The clear command clears out the dataset that is currently in memory. We need to do this before we can create or read a new dataset.

2.1 A small dataset

name      midterm   final
Smith       79       84
Jones       87       86
Brown       91       94
Adraktas    80       84 

2.2 Creating a dataset using the 'Data Editor'

. edit

The edit command opens up a spreadsheet like window in which you can enter and change data. You can also get to the 'Data Editor' from the pull-down 'Window' menu or by clicking on the 'Data Editor' icon on the tool bar.

Enter values and press return. Double click on the column head and you can change the name of the variables. When you are done click the 'close box' for the 'Data Editor' window.

. save grades
save grades, replace

The save command will save the dataset as grades.dta. Editing the dataset changes data in the computer's memory, it does not change the data that is stored on the computer's disk. The replace option allows you to save a changed file to the disk, replacing the original file.

. list
summarize

Let's list the contents and run some statistics on the new data set

2.3 Creating a dataset from an ASCII file

. clear

Now, assuming that you are in the statacls directory, let's download some files to work with. If you are not in the statacls directory use the cd command to get there.

The net from and net get commands are used to copy data and text files from the ATS web server to the local computer. If the files already exist in the statacls directory, use the replace option. The command would look like this: net get data, replace.

The infile command is used to read data from an external ascii file. The names of the variables are given followed by the keyword using which in turn is followed by the name of the file. str10 is not a variable name but indicates that name is a string variable up to 10 characters long.

The ASCII file called ascii.raw that looks like this:

"Smith"       79       84
"Jones"       87       86
"Brown"       91       94
"Adraktas"    80       84

2.4 Creating a dataset from a spreadsheet or database

. clear
type spread.raw
insheet using spread.raw
list

The insheet command is used to read data from a file created by a spreadsheet or database program. The values in the file must be either comma or tab delimited. The names are included in the file.

The spreadsheet file called spread.raw that looks like this:

name,midterm,final
Smith,79,84
Jones,87,86
Brown,91,94
Adraktas,80,84

3.0 Try the commands on your own

. clear
edit
save grades
save grades, replace
list
summarize
clear
infile str10 name midterm final using ascii.raw
clear
insheet using spread.raw

4.0 Can you answer these questions?

1. What should you do when you get the following message after the command, use hsb2, "no; data in memory would be lost?"
2. What is the difference between use grades and use grades, clear?
3. What is the difference between save grades and save grades, replace?
4. Consider the commands below:
   clear
   infile str10 name midterm final using ascii.raw
   insheet using spread.raw
   Do you think the "insheet" command will work? What should be done to make it work?

5.0 For More Information

• Statistics with Stata 5 Chapter 2 (especially pages 37-40)
• Stata Learning Modules
  Inputting Your Data into Stata
  Using and Saving Files in Stata