Using a local in stata to change values of variable. Dates in string form, identifiers and categorical variables, and pure numeric content trapped in string form need different actions. Recode recodes the string variable sex into the numeric variable nsex. When i tried, it said type mismatch i have tried the real and the encode commands, none of. In spss, recoding categorical string variables to numeric codes and converting blank strings to missing values can be done automatically using automatic recode. How can i change a string variable into a numeric variable. If a variable is string, then typically stata refuses to do calculations. Stata for econ capstone stata research guides at bates. Variables may either be recoded into numeric variables or into string.
String data is commonand examples include geographical information,gender information, think m, think f,or possibly date information. Stata can store numbers with differing levels of precision, as described in the table below. Unlike decode, sdecode creates an output string variable containing the values of the input variable as output by the list command and other stata output, instead of decoding all unlabelled input values to missing. This is a good example of how stata variables are different from spreadsheet columns. This module should be installed from within stata by typing ssc install strrec. If you have any questions please feel free to post them in the comments section below and i. String variables that seemingly should be numeric require some care. Instructor in this session,were going to explore string variables,and learn how can use stata to manipulate string information. The closest you can come to that is to convert the numeric variables to string, and then you can combine them. Stata tutorial canadian centre for health economics. This allows you to specify how you would like missing values in a string variable. May 14, 2017 this feature is not available right now.
You can use the to keyword to specify a list of variables or the all keyword to specify all variables in the active dataset the optional input format specification restricts the type modification to only variables in the list. The stata command destring and encode could be used to convert string variables to numeric variables. First off, you can convert a string into a numeric variable in variable view as shown below. If the variable is actually a numeric value that just happens to be stored as a string, see our faq. String variables may contain numbers, letters and other characters. You can download rmiss2 over the internet from within stata. Aug 05, 2019 the stata command destring and encode could be used to convert string variables to numeric variables. The output string variable may either replace the input numeric variable or be. Note that while using list, and some other data display commands, produces values that look like string dates, the actual values stored by stata are numeric. This module should be installed from within stata by typing ssc install multencode. How to download portable and cracked stata youtube. It is easy to use the numeric variable, but we may also want to keep the information. There are two cases in which you will want to convert string variables to numeric.
Instructor in this session,were going to explore string variables,and learn how can use statato manipulate string information. Quickly master the trick with a stepbystep example on downloadable practice data. How to convert many character variables to numeric. How can i quickly convert many string variables to numeric. String to numeric conversion problem with destring command. These variables were accidentally read into stata as string variables because they contain spaces, dollar signs, commas, and percent signs. Stata deals with missing variables in di erent ways depending on the command. For example, in the data set below, we have a numeric variable a coded 10 for gender and a string variable b also for gender but with more explicit information.
The first line of syntax reads in the dataset shown above. How can i turn a string variable containing dates into a. Ive got a variable countrycode in my dataset that uses iso numeric codes basically 3 numbers to identify which country each observation is from. In the display below, sindicates a string subexpression a string literal, a string variable, or another string expression and nindicates a numeric subexpression a number, a numeric variable, or another numeric expression. How to convert many character variables to numeric using a. In spss, how do i convert between numeric variables and. If the string variable contains anything but numbers, you can add the force option to tell stata to convert it anyway, but observations with any non numeric characters will get a missing value these limits are a substantial increase from those of intercooled stata with its 2,047 maximum variables, 80character maximum string length, and an 800. Written and illustrated tutorials for the statistical software spss. Download presentation tutorial on stata jill furzer institute of health policy, management, and evaluation canadian centre for health economics september 30, 2015.
How to create variables in stata using generate and egen course. Statas three numeric formats are denoted by a leading percent sign, %, followed by the string w. Stack overflow for teams is a private, secure spot for you and your coworkers to find and share information. Blue text is labeled numeric variables red text is for character variables called string variables in stata convert character variable to numeric make use of statas destring. Recode missing values coded with a string in stata. To be able to perform any mathematical operations, your variables need to be in a numeric format. The difference between string and numeric variables is crucial due to the fact that variable type dictates what you can or cannot do with a variable. The destring function is a good example of stata s builtin functions having a knack for knowing what youre trying to do and providing a pretty. The string option at the end allows it to be a string rather than a numeric value. One method of converting numbers stored as strings into numerical variables is to use a string function called real that translates numeric values stored as strings into numeric values stata can recognize as such.
How do i assign the values of one variable as the value labels for. In this quick tutorial, were going to look at how to recode a string variable as a numeric variable in the spss statistics program. They take up more memory and are not useful for your regressions, etc. Even though stata can handly string variables, it is clear in many respects that numeric variables are much preferred. If you have a string variable and want to convert it to a numeric variable, you can use the encode command. Theyre useful if your string variables contains a lot. You cant combine numeric and string variables into a single variable in stata. How can i see the number of missing values and patterns of missing. How do i convert string variables to numeric variables in. Data entered in stata can be classified either as numeric or string type. Stata module to encode a string variable nonalphanumerically into a numeric variable. Suppose that you have numeric data in a variable called x, but because of a mistake, x was made a string variable when you read the data.
Like so, working with string variables in spss is super easy. Spss variable types ssps has two variable types, namely numeric and string. The stata commands that well be using are the following, destring and tostring which convert string variables to numeric variables and back. You can recognize these in the data editor because they will be colored red.
I tried to split string but am not able to get it to do this. Alter type can be used to change the fundamental type string or numeric or format of variables, including changing the defined width of string variables options. Official stata provides the utilities encode and decode for conversion between string variables and numeric variables with value labels, and the utilities destring and tostring for conversion. To use the number function, you need to enclose the name of the string variable and a format for the new numeric variable. Spss string function converts numeric values to string values. You can download it by typing search labutil see how can i use the search. Changing string variables to numbers in stata youtube. The missing value for strings in stata is denoted by. I suspect you want to do this but without seeing your variable names its just guesswork. Typing in data, changing variable names, adding labels, and adding values duration.
Associated with each type of data is its storage type i. In the example above, a8 indicates a string variable eight characters long, and f2. May 29, 2019 convert variables from string to numeric in stata duration. How can i change the value stored in local macro from string to numeric. In order to do so, i need both the id variable and time variable to be numeric and not string. Convert character to numeric in r example for string. You can call it whatever you want, but the variable name goes inside the j option. To do this, you need to create a new variable using the compute command. We are here to help, but wont do your homework or help you pirate software. One way is to use the number function with the compute command. If your strings contain unicode characters or you are writing programs that will be used by others who might use unicode. Jul, 2017 convert variables from string to numeric in stata earnings management data. Copying data from the internet, csv files, or other sources into stata will record the date as a string variable, shown with red color.
Stata module to encode multiple string variables into numeric multencode creates new numeric variables. Fortunately, stata offers some easy ways for converting string to numeric variables and vice versa. For stata, a string is any data characterthat is not a numberor missing value denoted by the full stop. The program can process a large number of cases more efficiently with the numeric variable nsex than it can with the string variable sex. Posted 08192014 3508 views in reply to nketata you can control the import type for a field from excel via dbsastype option, but this is more of an infile method in that youll need to hardcode it for each file rather than automatically import the file. In this video i show you how to convert text data into numeric data. How can i convert string variables to numeric variables in.
Spss how to convert string variables into numeric ones. Most of the time, which kind you want to use for particular variables is clear and unproblematic, but surprisingly often, users face difficulties in making the right decision or need to convert variables from one kind to another. I have tried to convert it string to numeric using destring and it. This module may be installed from within stata by typing ssc install.
This chapter discusses the properties and uses of global numeric and string variables. What command can i use to select variables containing specific pattern in stata. In a case where your string variables are in fact strings e. In stata, we can use the command called labmask to create value labels for the. Quick table for converting different dates to stata format. I know this happens because the macro stored is a string. You may even get the cryptic message no observations, which. Although destring conversion of string to numeric form has a long history, it adopted in official stata version 75.
Stata represents missing values for numeric variables with a dot. The goal is to be able to start paneldata procedure. Before we can dive into the transformation of a character variable to numeric, we need to create an example character in r. This is often done using the automatic recode functionality of spss, but in this case were going to do it manually because of the extra control we get. Stata treats a missing value as the largest possible value. There may be times that you receive a file that has many or all of the variables defined as strings, that is. In the i option, you list all identifying variables. Convert spss string variables into numeric ones the right way. Basic video for converting many string variables to numeric using encode syntax in stata. You cant use numeric functions such as addition or subtraction on string variables. If you are referring to numeric variables for which there is a value label missing then you need to find out the corresponding numeric value and use that in your call to mvdecode. This video demonstrates how to convert categorical string variables to labeled numeric variables.
Variables containing stringscalled string variablesoccur in data for a variety of reasons. Before we can use the stata timeseries or paneldata capabilities, we need to convert the string date to a stata date. Listing nonmissing string variables in stata stack overflow. Running this command will cause stata to make a new numeric categorical variable wherein the data has labels that correspond to the old string values. Working with variables research guides at bates college. Hello member of stata list i have a variable which have value like 4w12345678. How to combine 2 numerical variables and 1 string variable. I suspect you want to do this but without seeing your variable. Changing string variables to numbers in stata duration. Recode missing values coded with a string in stata stack. Difficult destring to initiate panel data procedure. In the following article, ill provide you with all important information for the conversion of character vectors to numeric in r. If the first argument is a string, then all the remaining.
Stata takes float as the default storage type for its variables. I have two variables in stata, both numeric variables that have somehow been recorded as string variables. Since the default variable type in spss is numeric, you need to define your string variable in advance. Also, the replace option of tostring doesnt take other parameters. Numeric variables are doubleprecision floating point an d can be real or complex. I need them converted to numeric variables so that i can generate a new variable with them. Stata news, code tips and tricks, questions, and discussion.
How to convert many character variables to numeric using a macro. Stata using a local in stata to change values of variable. The second command formats the numeric value so that when stata displays the date, it is in a form that is easy for humans to read. String variables can hold an arbitrary number of bytes. The easiest way to convert string variables to numeric form is to use the encode command. With a force option, datasets containing numeric variables may also be transposed. Not least, most statistical procedures just do not accept string variables.
Stata module to recode string variables according to rules. There are several ways that you can change a string variable into a numeric variable. The great divide among data types in stata is between numeric and string variables. What command can i use to select variables containing. How to recode string variables in spss quick spss tutorial. If you have a string variable that has only numbers in it. We want to remove all of these characters and create new variables for date, price, and percent.
You can, however, extract one or more characters a substring from them, glue them together concatenate and a couple of other functions. The column provides a stepbystep guide explaining how to convert them oras the case may meritto leave them as they are. How to destring nonnumerical values within stata quora. Reed college stata help changing string variables to. For the fine points of programming with global variables, see accessing global variables and waves on page iv59. Additional missing data values are available, starting with. I cant apply it to many variables at once, so it may take way more effort than necessary. Stata module to decode a numeric variable into a string. Sometimes two variables in a dataset may convey the same information, except one is a numeric variable and the other one is a string variable. How can i quickly convert many string variables to numeric variables. Basic video for converting many string variables to numeric using encode syntax in stata with using loops. Users often find that stata is reading in most, or even all, variables as string variables, when most, or even all, areor should benumeric.
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