1. Creating a data set using the data editor 2. Importing an Excel data file

Transcription

1 Introduction This illustration describes two ways to enter data into Stata 1. Creating a data set using the data editor 2. Importing an Excel data file Example -. This data set has n=4 observations on 4 variables. The variables are of different types: string, date, and numeric. Tips - The variable id could be either string/character or numeric. Your choice. Date variables must be entered as string first, converted to date, and then formatted. id type: numeric dob type: date gender type: string/character weight type: numeric 1 3/26/1926 male /9/1956 female /1/1954 male /4/1951 female \STATA v 12 entering data.doc Page 1 of 7

2 1. Creating a Data Set using the Data Editor The following is a suggested approach. You might have a better one! Launch Stata. Tip Always begin your Stata sessions by opening a.log Recommended preliminaries (1) In the command window, define your variable names (all lower case suggested) and initialize values to missing (period for numeric, for string).. generate id=.. generate str8 dob_string="". generate str8 gender="". generate weight=. (2) Explicitly specify string variables as such. (3) Initially, your date variable a temporary name that makes clear that it is initially string. From the toolbar at top, click on data editor \STATA v 12 entering data.doc Page 2 of 7

3 Stata will give you an empty spreadsheet with the variable names you specified. Enter your data as you would if you were using Excel. Note numeric data will be shown in black, string data will be shown in red. \STATA v 12 entering data.doc Page 3 of 7

4 From the main menu bar Data > Variables Manager In the Variable Managers window, put your cursor over var1. Click to activate. Click on your first variable (id) to select. The dialog boxes at right, under Variable Properties will activate. Type in a label if you like. Click on Apply at lower right Then click on the Repeat for the other variables. Close Variables Manager All done entering data? Close Data Editor. You will be returned to the command window \STATA v 12 entering data.doc Page 4 of 7

5 In the command window: (1) Use the generate command together with the date function with the option MDY to convert the date data (entered as string) to a new date variable that Stata will recognizes as date data. (2) Use the format command to format your new date variable (otherwise any output will be incomprehensible!). generate dob=date(dob_string, "MDY"). format dob %tdnn/dd/ccyy. drop dob_string. list id gender weight dob male /26/ female /09/ male /01/ female /04/ (3) Drop the string variable version of your date variable. Tip! List a few observations to check your work. Tip! How to create a numeric 0/1 indicator of female. Note the double equal signs in the logical operator.. generate female=(gender=="female"). list id gender weight dob female male /26/ female /09/ male /01/ female /04/ Don t forget to save your data!. save "/Users/carolbigelow/Desktop/practice.dta" file /Users/carolbigelow/Desktop/practice.dta saved FILE > SAVE AS \STATA v 12 entering data.doc Page 5 of 7

6 2. Importing an Excel Data File Example Before importing an excel file into Stata, a few preparations in Excel are recommended. This excel data file has n=4 observations on 3 variables. It is saved as tiney.xlsx. It is then imported it into Stata v 12 where it is then saved as a Stata data set called tiney.dta Launch Excel Edit your column headings so that they are your variable names. Tip! Use lower case names Save your new Excel file and quit. FILE > SAVE (eg tiney.xlsx) EXCEL > QUIT EXCEL Launch Stata Use FILE drop down menu to import your excel data: FILE > IMPORT > EXCEL SPREADSHEET \STATA v 12 entering data.doc Page 6 of 7

7 Within Import Excel - Important - Check the box for Import first row as variable names. Click OK Don t forget to save your data! FILE > SAVE AS \STATA v 12 entering data.doc Page 7 of 7