How can i see the number of missing values and patterns of missing. Data entered in stata can be classified either as numeric or string type. How to convert many character variables to numeric using a. The output string variable may either replace the input numeric variable or be. Basic video for converting many string variables to numeric using encode syntax in stata with using loops. How to convert many character variables to numeric using a macro. The string option at the end allows it to be a string rather than a numeric value.
In a case where your string variables are in fact strings e. Difficult destring to initiate panel data procedure. String to numeric conversion problem with destring command. 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 missing value for strings in stata is denoted by. Stata represents missing values for numeric variables with a dot. The program can process a large number of cases more efficiently with the numeric variable nsex than it can with the string variable sex. Written and illustrated tutorials for the statistical software spss. These variables were accidentally read into stata as string variables because they contain spaces, dollar signs, commas, and percent signs. You cant use numeric functions such as addition or subtraction on string variables. Download presentation tutorial on stata jill furzer institute of health policy, management, and evaluation canadian centre for health economics september 30, 2015.
Before we can dive into the transformation of a character variable to numeric, we need to create an example character in r. 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 module should be installed from within stata by typing ssc install strrec. Stata for econ capstone stata research guides at bates. If you have any questions please feel free to post them in the comments section below and i. Stata module to recode string variables according to rules. Changing string variables to numbers in stata duration. 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.
You cant combine numeric and string variables into a single variable in stata. This chapter discusses the properties and uses of global numeric and string variables. How can i change the value stored in local macro from string to numeric. Instructor in this session,were going to explore string variables,and learn how can use stata to manipulate string information. How can i change a string variable into a numeric variable. What command can i use to select variables containing. 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. You may even get the cryptic message no observations, which. How to create variables in stata using generate and egen course.
To do this, you need to create a new variable using the compute command. Spss how to convert string variables into numeric ones. To use the number function, you need to enclose the name of the string variable and a format for the new numeric variable. The stata commands that well be using are the following, destring and tostring which convert string variables to numeric variables and back. You can download rmiss2 over the internet from within stata. Stata takes float as the default storage type for its variables. Basic video for converting many string variables to numeric using encode syntax in stata. Convert spss string variables into numeric ones the right way. The first line of syntax reads in the dataset shown above. Hello member of stata list i have a variable which have value like 4w12345678. Convert character to numeric in r example for string. Ive got a variable countrycode in my dataset that uses iso numeric codes basically 3 numbers to identify which country each observation is from. Stata deals with missing variables in di erent ways depending on the command. How to destring nonnumerical values within stata quora.
I have tried to convert it string to numeric using destring and it. Also, the replace option of tostring doesnt take other parameters. In spss, recoding categorical string variables to numeric codes and converting blank strings to missing values can be done automatically using automatic recode. They take up more memory and are not useful for your regressions, etc. To be able to perform any mathematical operations, your variables need to be in a numeric format. One way is to use the number function with the compute command. We are here to help, but wont do your homework or help you pirate software. I suspect you want to do this but without seeing your variable. With a force option, datasets containing numeric variables may also be transposed.
For stata, a string is any data characterthat is not a numberor missing value denoted by the full stop. 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. You can recognize these in the data editor because they will be colored red. How to download portable and cracked stata youtube. In spss, how do i convert between numeric variables and. Typing in data, changing variable names, adding labels, and adding values duration. How do i convert string variables to numeric variables in. Statas three numeric formats are denoted by a leading percent sign, %, followed by the string w. This video demonstrates how to convert categorical string variables to labeled numeric variables.
Changing string variables to numbers in stata youtube. I tried to split string but am not able to get it to do this. Even though stata can handly string variables, it is clear in many respects that numeric variables are much preferred. This allows you to specify how you would like missing values in a string variable. You can, however, extract one or more characters a substring from them, glue them together concatenate and a couple of other functions. String variables can hold an arbitrary number of bytes. The closest you can come to that is to convert the numeric variables to string, and then you can combine them. How can i turn a string variable containing dates into a. Instructor in this session,were going to explore string variables,and learn how can use statato manipulate string information.
Listing nonmissing string variables in stata stack overflow. If your strings contain unicode characters or you are writing programs that will be used by others who might use unicode. How to convert many character variables to numeric. If you have a string variable and want to convert it to a numeric variable, you can use the encode command. Reed college stata help changing string variables to. Variables containing stringscalled string variablesoccur in data for a variety of reasons. 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. Quickly master the trick with a stepbystep example on downloadable practice data. String data is commonand examples include geographical information,gender information, think m, think f,or possibly date information. 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. The magic here is to convert the string variable sex into a numeric variable called gender with an associated value label, a trick accomplished by encode. What command can i use to select variables containing specific pattern in stata. String variables that seemingly should be numeric require some care.
May 29, 2019 convert variables from string to numeric in stata duration. 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. Stack overflow for teams is a private, secure spot for you and your coworkers to find and share information. In order to do so, i need both the id variable and time variable to be numeric and not string. Stata module to encode multiple string variables into numeric, statistical software components s456993, boston college department of economics, revised 21 jan 2009. There are several ways that you can change a string variable into a numeric variable. I suspect you want to do this but without seeing your variable names its just guesswork. Stata can store numbers with differing levels of precision, as described in the table below. In the following article, ill provide you with all important information for the conversion of character vectors to numeric in r. Jul, 2017 convert variables from string to numeric in stata earnings management data. 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. 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. Aug 05, 2019 the stata command destring and encode could be used to convert string variables to numeric variables.
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. Like so, working with string variables in spss is super easy. First off, you can convert a string into a numeric variable in variable view as shown below. May 14, 2017 this feature is not available right now. Theyre useful if your string variables contains a lot. Recode missing values coded with a string in stata stack. When i tried, it said type mismatch i have tried the real and the encode commands, none of which are working.
Since the default variable type in spss is numeric, you need to define your string variable in advance. In stata, we can use the command called labmask to create value labels for the. 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. It is easy to use the numeric variable, but we may also want to keep the information. You can download it by typing search labutil see how can i use the search. Stata module to encode multiple string variables into numeric multencode creates new numeric variables. If the first argument is a string, then all the remaining. Dates in string form, identifiers and categorical variables, and pure numeric content trapped in string form need different actions. Additional missing data values are available, starting with. 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. There may be times that you receive a file that has many or all of the variables defined as strings, that is. Spss variable types ssps has two variable types, namely numeric and string.
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. This module should be installed from within stata by typing ssc install multencode. Recode recodes the string variable sex into the numeric variable nsex. 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. How can i quickly convert many string variables to numeric variables. Associated with each type of data is its storage type i. Stata module to decode a numeric variable into a string. The stata command destring and encode could be used to convert string variables to numeric variables. Users often find that stata is reading in most, or even all, variables as string variables, when most, or even all, areor should benumeric. I need them converted to numeric variables so that i can generate a new variable with them. 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. 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. If a variable is string, then typically stata refuses to do calculations. Stata news, code tips and tricks, questions, and discussion.
Spss string function converts numeric values to string values. Stata using a local in stata to change values of variable. Before we can use the stata timeseries or paneldata capabilities, we need to convert the string date to a stata date. Stata treats a missing value as the largest possible value. In this video i show you how to convert text data into numeric data. 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. I cant apply it to many variables at once, so it may take way more effort than necessary. How can i convert string variables to numeric variables in. Variables may either be recoded into numeric variables or into string. Using a local in stata to change values of variable. How can i quickly convert many string variables to numeric. Fortunately, stata offers some easy ways for converting string to numeric variables and vice versa. 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. How to combine 2 numerical variables and 1 string variable.
Quick table for converting different dates to stata format. Stata module to encode a string variable nonalphanumerically into a numeric variable. In the example above, a8 indicates a string variable eight characters long, and f2. Working with variables research guides at bates college. I know this happens because the macro stored is a string. How do i assign the values of one variable as the value labels for. For the fine points of programming with global variables, see accessing global variables and waves on page iv59.
You can call it whatever you want, but the variable name goes inside the j option. Recode missing values coded with a string in stata. In this quick tutorial, were going to look at how to recode a string variable as a numeric variable in the spss statistics program. Numeric variables are doubleprecision floating point an d can be real or complex. This is a good example of how stata variables are different from spreadsheet columns. If the variable is actually a numeric value that just happens to be stored as a string, see our faq. We want to remove all of these characters and create new variables for date, price, and percent. In the i option, you list all identifying variables. So basically i want to take x and make two new variables variable x2 has only the last character of x and variable x1 has all but the last character of x.
Although destring conversion of string to numeric form has a long history, it adopted in official stata version 75. String variables may contain numbers, letters and other characters. I have two variables in stata, both numeric variables that have somehow been recorded as string variables. The great divide among data types in stata is between numeric and string variables. Stata tutorial canadian centre for health economics. When i tried, it said type mismatch i have tried the real and the encode commands, none of. Copying data from the internet, csv files, or other sources into stata will record the date as a string variable, shown with red color. The easiest way to convert string variables to numeric form is to use the encode command.
How to recode string variables in spss quick spss tutorial. The goal is to be able to start paneldata procedure. 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. There are no system missing values in string variables. This module may be installed from within stata by typing ssc install. If you have a string variable that has only numbers in it.
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