Oct 05, 2010 to concatenate is to join the characters of 2 or more variables from end to end. Data entered in stata can be classified either as numeric or string type. The variable does not contain nonnumeric characters. Wordstat combines natural language processing, content analysis and statistical techniques to quickly extract topics, patterns and relationships in large amount of text. Stata program called mdesc that counts the number of missing values in both. Stata is a complete, integrated statistical software package created by statacorp lp. This value can be one or more blanks, or a numeric code such as 9999. Spss vs stata top 7 useful differences you need to know. Sep 27, 2016 introduction to stata generating variables using the generate, replace, and label commands duration.
How can i extract a portion of a string variable using. Date prev date next thread prev thread next date index thread index. In stata, how do i calculate frequency for variables and save the results into a new data set, using the contract command. Var2 is a string variable even though you see numbers. When i add the variable to the dataset, stata recognizes it as a string variable. How can i quickly convert many string variables to numeric. How to count total number of string value occurrence per observation in stata.
Nothing but guesswork leads to the syntax you tried. It would also be nice if there was a way to check if 10th value is tied with 11th, 12th, etc. The count command has one simple role, to count observations in. I had a big dataset on prescriptions in patients in wide stata format. Wordstat for stata was created to allow stata and stata 15 users running under windows, to apply text analytics techniques on any string variables stored in a stata data file. His problem is how to extract the state, districts, etc. Throughout, bold type will refer to stata commands, while le names, variables names, etc. In stata, this can be done by using either gen or egen. Stata can handle this using standard commands see my date variable is a string, how can i turn it into a date variable stata can recognize. We will show some examples of how to use regular expression to extract andor replace a portion of a string variable using these three functions. I need to create a variable nvals that counts the number of unique strings found for any given respondent in a to z. Below we use the infile command, where we specify variable names and the column numbers that their corresponding values inhabit clear infix id 12 a1 34 t1 56 gender 7 a2 89 t2 1011 tgender 12 using schdat.
How can i convert string variables to numeric variables in. What command can i use to select variables containing. The easiest way to tell if this is the case is to look at the variables window. Stata is available on the pcs in the computer lab as well as on the unix system. Commaseparated file with variable names our first data will come as a spreadsheet, often managed or created by programs such as excel. Even so, because the variable is defined as str2, stata cannot perform any kind of numerical analysis of the variable science. Moreover, as bug fixes and new features are issued frequently by statacorp, make sure that you update your stata before posting a query, as your problem may already have been solved. As joerg said, just using length or strlen to count the characters is what you want. Basics of stata this handout is intended as an introduction to stata. You can only define missing values for string variables whose length is eight or. How can i quickly convert many string variables to numeric variables. In stata, how do i calculate frequency for variables and. Counting substrings within strings the stata journal. Posted on 20 january 2011 by mitch abdon somebody asked how to count the number of occurrences of a string within a string.
Associated with each type of data is its storage type i. But no one wants to scroll through what may be screenfuls of describeoutput. Dec 01, 2016 this video demonstrates how to convert categorical string variables to labeled numeric variables. If the variable is actually a numeric value that just happens to be stored as a string, see our faq. Although the variable science is defined as str2, you can see from the list below that it contains just numeric values. Counting distinct strings across a set of variables stata.
In this example, we have dates entered as a string variable. Aug 30, 2016 see my playlist, introduction to econometrics with stata, for more updated videos. It is composed of in this order the 2digit region code, the 2digit province code, the 2digit municipaltiy code, and the 3digit barangay code. You can only define missing values for string variables whose length is eight or less what spss calls short string variables. Sometimes, for whatever reason, stata incorrectly calls a categorical variable a string variable. Then, in stata type edit in the command line to open the data editor. The first line of syntax reads in the dataset shown above.
Suppose you have a 6digit numeric observation id, code, where the first 2 digits represent geographic code and the last 4 digits represent unique observation codes, and you want to generate a new variable, reg, that represents the 2digit geographic code. Stata programs of interest either to a wide spectrum of users e. 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. Introduction to stata generating variables using the generate, replace, and label commands duration. Point the cursor to the first cell, then rightclick, select zpaste. In destring complication, anup asked how to split a string variable. The functions mod and round are also covered at the end for your reference. To begin with, we have always been warned against using count data in ols regression. In stata, you can use the contract command to calculate frequency for variables and save your. Stata news, code tips and tricks, questions, and discussion. This video demonstrates how to convert categorical string variables to labeled numeric variables. About asdoc asdoc is a stata program that makes it supereasy to send output from stata to ms word.
How to count total number of string value occurrence per. Select two or more variables of the same type numeric or string. String processing is fairly easy in stata because of the many builtin string functions. See my playlist, introduction to econometrics with stata, for more updated videos. The command egen newvar count stringvar, by groups does not work type mismatch r109. In stata, how do i calculate frequency for variables and save. For example, if i have the following data, i want to generate new variables countss, countsm, and countsg that contains the number of occurrences of ss, sm, or sg in variable awards. To concatenate is to join the characters of 2 or more variables from end to end. In his case, he has a variable of the form 28180018021832ob where 28 represents state code, 18 represents districts code, 0018 represents subdistricts code and 02183100 represents village code. Stata takes float as the default storage type for its variables. Counting unique values in a series of string variables. I want to count the number of characters in each responsestring and generate a new variable containing this number. It provides a wide range of statistical analysis, data management, and graphics.
A few sessions with stata will show users at least one way of approaching this problem. A simple histogram can show us that this is a good recommendation. The first case most often occurs when importing data from another source. Count observations by group statalist the stata forum. For example, in excel, we can save data as a commaseparatedvalues format. Lets analyze the variable daysabs to see if there is an effect due to gender and ability as measured by mathnce and langnce. How can i see the number of missing values and patterns of missing. Most statistical programs including sas, spss, and stata will automatically remove. What im looking to do is get a number for amount of 1s i have in each state, relative to the state sample. Create a date variable from a date stored as a string optimize the storage of variables round a continuous variable stata s expression builder examining data identify and remove duplicate observations labeling, display formats, and notes label variables label the values of categorical variables change the display format of a variable add notes. Here is one example where you need to preserve the numerical format for strings. Besides displaying output in the results window, stata stores the results of some commands so that you can. So, i want to identify in var2 how many digits per line var1 has. As example, suppose we have the variables var1, var2, and var3.
Nov 06, 2011 this is an easy way to get see how many observations are in your dataset, but it can also count the number of observations based on a variable which groups observations. To indicate a missing value in a string variable, you need to use the missing values command and assign a value to missing cases. Using the egenmore i have already counted the number of words using nwords, but i cannot find the counterpart for counting characters. The easiest way to convert string variables to numeric form is to use the encode command. How can i count how many cases are missing in a string. Installation the program can be installed by typing the following from the stata command. The following document provides an example of how to create string variables from numeric variables, and then concatenate string variables into one. How to generate a string variable out of a labeled numeric variable stata. Its value is always the current observation being worked with. Do not loop over observations, as it is usually not the best way to do something. What command can i use to select variables containing specific pattern in stata.
Ways to count the number of unique values in a variable. Then i converted the variable to a numeric one and then the count worked. Among these string functions are three functions that are related to regular expressions, regexm for matching, regexr for replacing and regexs for subexpressions. The entries in variable code, with numeric format %06.
I have a data set with a dummy variable for eitc eligibility. I get a type mismatch when attempting to count a string variable through egen. The following example loads up an automotive dataset included with stata and counts the number of foreign and domestic cars in it. An example of when one might need to do this is if they needed to append several variable sets together, and they needed a unique identifier the included information about the source data set. The following document provides an example of how to create. Spss has spss analytic server, spss modeler, spss statistics and different variable types such as string and numeric and has different variable formats whereas stata has different word documents to be created to automate the reports and generate results and graphs in tabular and text formats. On april 23, 2014, statalist moved from an email list to a forum, based at. Spss statistics and different variable types such as string and numeric and has different variable formats whereas stata has different word documents to be created to automate the reports and generate. Click define values and specify which value or values should be counted. Stata is general purpose software package for statistical analysis developed by stata corp in the year 1985. The import excel command was introduce in stata 12. Users of any of the software, ideas, data, or other materials published in the stata journal or. Examples of the types of papers include 1 expository papers that link the use of stata commands.
Similarly byte, int and long are usually used to hold integers. I have concatenated the variables into a single string variable, and then concatenated all of the rows into a single space delimited string per id see below. I was trying to do the second one, which you mentioned my command is legal. Counting occurrence of strings within strings stata daily. Jan 20, 2011 somebody asked how to count the number of occurrences of a string within a string. Counting distinct strings across a set of variables. If a variable is a string, the type will be str followed by some number.
We are here to help, but wont do your homework or help you pirate software. The psgc is a 9digit code that represents all geographic units in the philippines from the largest region to the smallest barangay or village. There are at least 3 convenient ways to count the number of distinct values contained in a variable. Instead, you have to use first, last, firstnm, or lastnm which is fine if the string variable is constant within the. Oct 01, 2010 there are at least 3 convenient ways to count the number of distinct values contained in a variable. Counting distinct strings across a set of variables author nicholas j. The latest versions of stata added many new features, including a long string data type allowing one to store along with numerical and categorical data, documents up. How to extract few letters of a string variable in stata. Although, for the best advise on stata, statalist is the best place to ask. Optionally, you can define a subset of cases for which to count occurrences of values. I was trying to count cases with the following command. The following document provides an example of how to. Reed college stata help changing string variables to. Wordstat for stata content analysis and text mining tool.