Variables being numeric or string is in the first instance a matter of variable type or storage type. Stata module to check the values of a created variable. Spss vs stata top 7 useful differences you need to know. Now that you understand statas basic syntax, youre ready to start working with your data. Nov 05, 2011 whether you are programming or trying to retrieve values calculated in stata, your best bet is probably to use the return list command in stata. It pays to develop a convention for naming variables and sticking to it. Not all characters in the keyboard, however, are allowed in naming variables. This stata faq shows how to check if a dataset has duplicate observations. The first one declares a variable of type int with the identifier a. How do i check for nonlinear and nonmonotonic effect. For a list of topics covered by this series, see the introduction. So its difficult to know is the variable having date value or date time value. Linear regression analysis in stata procedure, output and. You should select the type of graph you want based on the type of variable or variables you wish to display visually.
In this case, you want to convert the actual variable, not the format type see here. Stata is available on the pcs in the computer lab as well as on the unix system. I am doing some processing in my program depending up on the varia. Variable names can have up to 32 characters, but many commands print only 12, and shorter names are easier to type. Additional data types store text, integer or singleprecision values, or a combination of related data in a single variable. There is no need to encode the type of the variable in its name.
Stata module to check whether a variable exists or. Linear regression analysis using stata introduction. I note this information about the variables in my wage dofile. So from my point of solving this particular problem the ideal way would be to check if the variable is numeric or character. We can check to see if the data came in right using the list command. While it had its uses, with a modern ide that supports intellisense type behaviours its not necessary to include the type of the variable in its name. Linear regression, also known as simple linear regression or bivariate linear regression, is used when we want to predict the value of a dependent variable based on the value of an independent variable. Throughout, bold type will refer to stata commands, while le names, variables names, etc. Even so, because the variable is defined as str2, stata cannot perform any kind of numerical analysis of the variable science. Cross tabulations, also known as contingency tables, are statistical analysis that examine the relationship between two or more variables. Stata names are case sensitive, age and age are different variables. The second one declares a variable of type float with the identifier mynumber. But often numeric variables are represented by the float type.
This is the second of two stata tutorials, both of which are based thon the 12 version of stata, although most commands discussed can be used in. Linear regression using stata princeton university. Any way to check datatype of a variable date or da. Many variables may be represented by the byte, int or long types, which require much less space than the float or double types. The guide will help beginning users to quickly get started with their econometrics and statistics classes. Working with data this is part four of the stata for researchers series. I focus explicitly on the foundations of using such software and ignore statistical procedures. Examples of the types of papers include 1 expository papers that link the use of stata commands. Stata module to check whether a variable exists or not in a dataset, statistical software components s455501, boston college department of economics, revised 26 sep 2005. This document is an introduction to understanding and using stata, a software package. Stata is widely used in social science research and the most used statistical software on campus.
The first example will use commands available in base stata. But no one wants to scroll through what may be screenfuls of describeoutput. How exactly do i check for nonlinear and nonmonotonic effect in stata. At worse it can make the code harder to read if you have to change the type of the variable in the future. Spss has licensed software that can be used as trial ware or saas software as a service.
Having said that, the type in a variable of type int has nothing to do with int. I recently resolved an issue where a difference in set type between two different computers led to different results when running the same dofile, with stata on one computer defaulted to float and the other to double. Although the variable science is defined as str2, you can see from the list below that it contains just numeric values. If the vtype function returns a value to a variable that has not yet been assigned a length, by default the variable is assigned a length of 1. Note particularly that if you create new variables from within stata with the help of generatereplace, the new variable will be of the float type by default. Data analysis with stata 12 tutorial university of texas. Review and cite stata software protocol, troubleshooting and other methodology information contact experts in stata software to get answers. If that results in renaming, preserving the first 31 characters and suffixing a. Cross tabulations advanced stata gsu library research. A variable can have one or several values information for one or several cases. You cannot get means, you cannot do a regression, you cannot do an anova, etc. Vtype returns n for numeric variables and c for character variables. In this article youll learn how to create new variables and change existing variables.
Data analysis with stata 12 tutorial university of texas at. Then, in stata type edit in the command line to open the data editor. Ive been browsing the stata help forums and i didnt see a solution to this issue anywhere, other than to destring the variable. This module may be installed from within stata by typing ssc install checkvar. If youre new to stata we highly recommend reading the articles in order. How do you use the commands rename, renpfix, and renvars to rename variable names. The variables may contain numeric values, but if they are defined as type string, there are very few things you can do to analyze the data. To get a general description of the dataset and the format for each variable type describe. If you are new to stata we strongly recommend reading all the articles in the stata basics section. For many of stata s commands particularly statistical ones, statistics generated or other data are saved in scalars, matrices, or macros. Additional data types store text, integer or singleprecision values, or a. When stata imports from excel with the firstrow option specified, if it encounters wouldbe variable names that are over 23 characters, it truncates them to 32 characters. By default, matlab stores all numeric variables as doubleprecision floatingpoint values. Point the cursor to the first cell, then rightclick, select zpaste.
You can always change a string variable to a longer string type. Stata module to check the values of a created variable, statistical software components s436101, boston college department of economics, revised 16 nov 2017. Often when importing data, stata can mistake a numeric variable for a string variable. Stata statistical software provides everything you need for data science and inferencedata manipulation, exploration, visualization, statistics, reporting. Stata recognizes a line starting with or as text and not a command. Stata is general purpose software package for statistical analysis developed by stata corp in the year 1985. There may be times that you receive a file that has many or all of the variables defined as strings, that is, character variables. Vtypex, however, evaluates the argument to determine the variable name. However, you can only change a string variable to a shorter string type. Stata is general purpose software package for statistical analysis. Any way to check datatype of a variable date or datetime sas. Do you prefix variable names with an abbreviation of the.
There are various date and date time formats can be assigned to a variable. This document is an introduction to using stata 12 for data analysis. Basics of stata this handout is intended as an introduction to stata. The function then returns the type character or numeric that is associated with that variable name. The following image shows the results of these two commands. Spss supports different operating systems such as windows, mac os, linux on z systems, unix and linux. I would like to check for type of variable string, numeric, etc in a program, and then take action on the basis of the type. Software engineering stack exchange is a question and answer site for professionals, academics, and students working within the systems development life cycle. Check datasets for variables statalist the stata forum. This document briefly summarizes stata commands useful in econ4570 econometrics and econ6570 advanced econometrics. Using stata efficiently to understand your data the. Mar 08, 2019 cross tabulations, also known as contingency tables, are statistical analysis that examine the relationship between two or more variables. Before you begin doing econometric analysis, make sure youre familiar with your data and how to view it in the popular stata software.
Hello all, is there a way to get stata to return the storage type for a variable. Stata manuals some are available at the pcl for checkout 2 statas own website has a modest amount of faqs in the support section. For the latest version, open it from the course disk space. How to check whether a variable is string standard i often find that commands dont work, because i have forgotten the to denote a string or the other way around. Is there any way to check a variable is holding date value or datetime value. This particular variable is of type numeric or character based on the type of the xml file. The second type of correlation is the normal correlation which takes the entire data set as one and calculates the correlation for all valid values. This information is available to you in other ways. For many of statas commands particularly statistical ones, statistics generated or other data are saved in scalars, matrices, or macros. Inputting your data into stata stata learning modules. This document briefly summarizes stata commands useful in econ4570 econometrics.
When stata does this, the number will look right when you browse, but attempts to run commands will turn up zero observations. A stata variable name can contain up to 32 characters in any version of stata small, stataic, statase, or statamp. A few sessions with stata will show users at least one way of approaching this problem. The mvmeta package of stata software is based on a multiple regression model to. This guide is not designed to be a substitute to any other official guide or tutorial, but serve as a starting point in using sas and stata software. Whether you are programming or trying to retrieve values calculated in stata, your best bet is probably to use the return list command in stata. Do you prefix variable names with an abbreviation of the variable types. The upperleft pane displays the stata commands that were entered in the editor lowerright pane. How to redetermine column type in stata stack overflow. Stata is a software package popular in the social sciences for manipulating and summarizing data and conducting statistical analyses. The lowerleft pane lists the variable names, and the stata results pane upperright, black background.
106 832 1169 758 1399 171 698 1041 310 1009 819 1268 1068 489 954 1054 549 1182 681 547 226 534 504 730 1436 267 1499 435 599 496 463 187