Stata merge multiple variables. Basically, + means concatenation with strings (i.

Stata merge multiple variables. The example below shows appending two files containing height data of different individuals into one single file. Stata 16 and 17 has data frames — keeping multiple datasets in memory simultaneously. Appending datasets is not the […] Aug 27, 2015 · Hi, I have two datasets each containing data on certain firms. Using STATA 14 I don't see the Apr 5, 2023 · You can merge on a varlist, namely one or more identifier variables. Example 4: Record results in another frame Apr 18, 2011 · Merging concerns combining datasets on the same observations to produce a result with more variables. input famid str4 name inc 2 A common problem in data management is combining two or more variables with missing values to get a single variable with as many nonmissing values as possible. The file names are 1. I want to combine two tables. dta file). gen strboth = strvar1 + strvar2 gen strboth2 = strvar1 + " " + strvar2 Also check out -egen, concat ()-. Mar 10, 2015 · As long as the variables are the same in the two datasets and we only need to add observations for the new measures we are interested in vertically, we can use append to combine these data. If you’re running modern Stata, type help frames, click the link to the PDF manual, and start reading. These variables are continuous and categorical variables. I think your problem is you just need to do an m:1 merge, instead of a 1:1. So far I have been trying with: gen maleage = min (agegroup, sex), generate Nov 16, 2022 · Use Stata/MP or Stata/SE. e. . stata. Merging basically amounts to adding variables -- columns of new information -- from another dataset to the existing dataset. When it comes to combining datasets, the alternative to merging is appending, which is combining datasets on the same variables to produce a result with more observations. In its simplest form from past Stata versions (the command above), datasets are merged based on their observation (or row) order (e. ucla. Aug 14, 2024 · Merge and Append Using Stata: How to Merge and Append Datasets This guide discusses basic techniques to merge and append datasets using Stata. I found the combine function, which is not helpful since the goal is to plot the lines in the same graph. There are two constellations: You may have two (or more) data sets about a number of observations (cases, objects). The data set used in these examples can be obtained using the following command: In this article, we’ll explain how to create new variables in Stata using replace, generate, egen, and clonevar. Feb 16, 2025 · In an m:m merge, if both datasets contain multiple rows for the same key variable (s), Stata will combine every possible match from both datasets, and in most cases, this is not what is required. Description append appends Stata-format datasets stored on disk to the end of the dataset in memory. Jan 23, 2018 · I am trying to merge 2 datasets based on 2 variables. I want a > var to look like > 440010. May 1, 2023 · I built a sample description table in Stata 17 and have recently switched over to Stata 18. merge can also perform sequential merges Aug 25, 2022 · I have these two datasets for instance, I am trying to merge them in Stata which usually requires the identifier variable to have the same column name. The csv files are all from google trends and should be the exact Nov 16, 2023 · I want to merge the data set using teh first one. Dec 31, 2023 · Have one predictor variable of interest, but several different outcome variables? Are all the outcome variables scaled the same way? If so, you can combine multiple “marginsplots” together Merge two datasets by adding new variables in STATA | Road to PhD Road To PhD 1. but there is nothing odd about two variables jointly identifying as in your case. 871, and in fact most interesting research, require combining data sets. How would I perform this in STATA? Thanks in advance for any help with this! How do I combine two string variables, one with “states” and one with the “state” code? Hi! I’ve spent almost the entire day with this issue and haven’t found anything that can solve my problem that shouldn’t be this difficult. You will probably also want to look into the keep() option in there. See [U] 23 Combining datasets for a comparison of append, merge, and joinby. If filename is specified without an extension, . See the manual entry for examples. In the above example, you don't have to merge repeated values of med_income from the counties frame onto your persons data. Nov 16, 2022 · There are only 3 observations in your master dataset, yet, when you do the merge, there are 4 observations that have a _merge code of 3 (meaning the observations are in both datasets). To combine these two les in Stata, you use the append command. Because I am new to Stata I use the graphics toolbar instead of trying to type the code myself. merge 1:1 Try using this if you’re unsure. dta, and 3. The canonical example for Stata users is given by cross-combinations of foreign and rep78 in the auto data. Nov 16, 2022 · Home / Resources & Support / FAQs / Stata Graphs / Bar chart with multiple bars graphed over another variable Bar chart with multiple bars graphed over another variable Learn about Stata’s Graph Editor Jan 26, 2016 · Well, Stata means exactly what it says. We will call the datasets one. dta has Apr 8, 2023 · Stata- How to combine a multiple choice set of variables into one Asked 2 years, 6 months ago Modified 2 years, 6 months ago Viewed 587 times Feb 6, 2017 · However, right now I have multiple observations with the same id and same date, but with different values on some dummy variables. I want the variables that have the same name and meaning to combine in the merged dataset. Therefor, I looked for a command in Stata that can match the string variables. oarc. Merging two data files with the same unit of observation Note: If using panel data, varlist must uniquely identify both individual and year merge m:m Rarely used Combining datasets using Stata is a frequent task in data analysis MERGE You merge when you want to add more variables to an existing dataset (type help merge in the command window for more details) What you need: Both files should be in Stata format Both files should have at least one variable in common (id) Step1. Typically, this problem arises when what should be the same variable has been named differently in different datasets. com> Prev by Date: st: using round time numbers on the x-axis of a stata graph Next by Date: st: Re Re: How to merge datasets when there are missing values in the matching variables Previous by thread: Re: st: How to merge datasets when there are missing values in the matching variables Dec 13, 2022 · Hello Everyone, I want to merge three files using macros and foreach loop. edu Jul 11, 2024 · Each variable occupies a column in the spreadsheet. It concatenates varlist to produce a string variable. Each file has two variables. For example, we have a file containing dads and a file containing moms as shown below. This article provides a comprehensive guide to merging data in Stata, detailing the process, syntax Merge – adds variables to a dataset. The common variables must have the same name. Jun 12, 2020 · Merging two datasets with many of the same variables 12 Jun 2020, 09:29 Hi, I want to merge two Stata datasets (both with >300 variables), of which ~200+ of the variables have the same name and the same meaning. In my sample there a 3,337 out of 7,001 who responded yes to both, so the new variable should have 3,337 Nov 16, 2022 · Combine multiple tables obtained with -table- or -dtable- using -collect-. merge can perform match merges (one-to-one, one-to-many, many-to-one, and many-to-many), which are often called joins by database people. Unfortunately, the spellings of firm names are different across the two datasets. Finally, I want to merge the two variables together to make a single variable and compute the mean score with at least one non-missing variable. We would now like to use a series of examples that shows how merge treats nonkey variables, which have the same names in the two datasets. Type help merge for details. The following example and figure illustrates the default behavior of twoway, histogram May 29, 2018 · The use case for attempting to combine locals is just to create a binary variable to flag whether someone received a final vaccine in a series (that has multiple stipulations). The variables are string except for the id, and there exist some duplicate entries for some Mar 7, 2018 · Hi all, I'm currently trying to combine two dummy variables together to form one consolidated variable, but haven't been able to produce the result that I want. Append is used when u want to add additio Oct 8, 2019 · How can I combine (sum) only two observations to create a new observation, while maintaining the rest of the data? In the below example I would like to combine Alabama and Alaska to create a new observation called 'Alabama & Alaska' with the sum of their populations. 1. Values of string variables are unchanged. They are both yes/no variables, both of them coded as 0=no 1=yes. However, when multiple histogram graph types are specified, bins are constructed separately for each series. This module will illustrate how you can combine files in Stata. csv and . The first I found merge s on identifier and time, which is common in panel data. Johannes if the second variable is a string, you can concatenate it with state . Suppose you have two string variables (strvar1 and strvar2) and want to combine them, you can simply type gen combinedvar=strvar1 + strvar2 May 29, 2024 · Prerequisites Change your directory so that Stata can find your files. Learn how to use frames, store results, and link them to work across multi-level datasets. The commands frlink and frget are used to link data frames and get variables (respectively) when using frames. May 4, 2018 · Hello all :-) Now I have a question about combining the data from two variables (in the same data set) into one variable. country names, etc. The first column/variable "SURVEY" represents whether the observation is from survey 1 or 2 Mar 9, 2016 · Create a new variable (combining two variables) 09 Mar 2016, 03:55 Hello, I am working with a panel data and I need to create a variable which will combine both city and country names: I have two separate variables country and city. dta is assumed. As evident from the data window, there are two types of variables in the data. Concatenation, or joining together, of strings or other values, possibly with extra punctuation such as spaces, is supported in Stata by addition of strings and by the egen function concat(), which concatenates values of variables within observations. These commands enable you to combine two or more data sets into a single set of data. The first table summarizes the sample selection criterion and tells me how When you perform a merge, if you have the same variable in both datasets, Stata will automatically keep the master data as authority. However, in the stata command it says, merge works only when both the files have same variable. Explore techniques, To visualize this, import a data set using the following command: Download Example File use "combine graphs. One variable is all of the states and the other variabel is the state code. This makes little sense without an example. dta format. Import data sets in . Not each caseid in one dataset has to have an equivalent in the other dataset, but unless there is a certain amount of overlap you will not be inclined to merge As I don't have sufficient number of cases when I take into account my covariates, I now need to combine these four variables to create 1 variable; 0=no > diagnoses of hypertension, and 1=diagnoses of any type of hypertension (in any of the four variables). yao@gmail. Explore each dataset separately before Feb 8, 2017 · Here, "name-of-second-dataset" (called the "using dataset" by the Stata people) is merged to the data in memory (called the "master dataset"), assuming that each value of variable "caseid" is present only once in each of the data sets. 1 (Access1, Access2). Unfortunately, most (if not all) of the other variables have different names. If the pattern of only one variable non-missing prevails throughout your data, then what you really want is a new variable that just picks out the non-missing value. Combining datasets using Stata is a frequent task in data analysis MERGE You merge when you want to add more variables to an existing dataset (type help merge in the command window for more details) What you need: Both files should be in Stata format Both files should have at least one variable in common (id) Step1. Stata, a powerful statistical software package, offers robust capabilities for performing various types of data merges. What does "combine" mean? Alternatively, in what sense can you add (which is what + means) 15 gender variables or 15 age variables?. dta (called the using dataset), matching on one or more key variables. We also see if we want to combine them into a sing Nov 24, 2020 · Combining strings into one variable I’m again playing around with strings in Stata and need to combine (string) variables with (string) variables as well as strings in locals with string variables. Stata’s treatment of missing values means that the combination needs a little care, although there are several Nov 19, 2019 · Greetings Stata Users: I am trying to generate a variable that has the categories of the outcome of interest (1 being the outcome of interest) that I Sep 21, 2016 · Good questions here show precise data examples and some attempt at code. dta, 2. Basically, + means concatenation with strings (i. One is the length If you have two or more categorical variables, you may want to create one composite categorical variable that can take on all the possible joint values. dta",clear For combining multiple graphs, the imported data can be used for the demonstration. dta If both datasets have the exact same variables, then Stata will simply add all the cases to the end of the current dataset. Mar 31, 2016 · I realize that there is a Stata forum with this exact title, but I did not find its syntax all that helpful, especially since my datasets are a bit different. From: shihying yao <berkeley. I'm trying to create a new variable that contains the information of those 5 groups divided by gender, something like: group 1 Female, group 2 Male, group 3 Female, group 3 Male, etc. Discover how to effectively combine categorical variables in Stata for better data analysis. If so, you need to reshape long. Yes. In fact, you knew that already, or you probably wouldn't have tried to include nper in the merge key as it would have been superfluous. If any filename is specified without an extension, . My two dummy variables are: wtrunemployed (which can take the value of 0 or 1) and wtrexitlabforce (which can take the value of 0 or 1). I have tried the command “generate = pre_Q2_2 + pre_Q33_2 but that May 27, 2011 · Multiple-key merges arise when more than one variable is required to uniquely identify the observations in your data. merge can also perform sequential merges Sep 4, 2015 · Dear Stata listers, I have to merge two data sets. At a wild guess you have data on up to 15 members of a family and wish to tabulate ages and genders. In this column, I discuss basic techniques for concatenating values of variables over observations, emphasizing simple loops that can In this video, we discuss how to convert a categorical string variable into a numerical variable in Stata. In […] Mar 2, 2020 · But I also have a question for you: in your example data, in each observation, only one of the four variables has a non-missing value, so you aren't really concatenating anything. Your dataset1 contains multiple observations that have the same value of number. 13K subscribers Subscribe Dec 15, 2024 · Merging data in Stata is a powerful tool that allows users to combine data from different sources to answer research questions. Instead, those values are accessed on-the-fly through the alias variable, med_income. I have two datasets. dta. Examples will include appending files, one to one match merging, and one to many match merging. To work with information contained in two or more . With the new observation, the previous records will need to be deleted. ). 8. append and merge. By following the steps outlined in this article, you can merge data in Stata with ease. I want to combine the variables in such a way that the data from one variable can replace the missing values from the other. Nov 16, 2022 · All of that is handled. See full list on stats. Appending data files When you have two data files, you may want to combine them by stacking them one on top of the other. https://www. If you do not have Stata/MP or Stata/SE, please continue with this FAQ. I have 2 variable which I am trying to combine into one. Alias variables can result in significant memory savings. Not each caseid in one dataset has to have an equivalent in the other dataset, but unless there is a certain amount of overlap you will not be inclined to merge Discover efficient techniques for merging datasets in Stata. edu> st: Re: Combining multiple observations into one observation with multiple variables From: Conor Hughes <cbhughes Hello! I have a category called agegroups divided into 5 groups and a category called sex divided into 2 groups (Male and Female). Nov 16, 2022 · How do I perform multiple operations on data records if a condition is met? We wish to merge these two datasets, but either 1) one of the datasets has a string variable for state and the other an encoded variable or 2) although both are numeric, we are not certain that the codings are consistent. If string make sure the categories have the same spelling (i. HTH Joseph On Sat, Sep 12, 2009 at 9:54 AM, Johannes Schoder < [email Mar 29, 2021 · How to combine two variables to create a new one? 29 Mar 2021, 02:24 Hello, I am working with a dataset with merged data from 2 survey rounds (2005 & 20011). 0f") If you want to attach the names to the county code, you'd need to download a list from elsewhere and merge into your data. Assuming > Second, you can combine these two string variables just by > . I am using the menu options "Data -> Combine datasets -> Merge two datasets", but only about half of the observations matched. Mar 30, 2017 · I am currently aiming to create an identification variable in order to identify the flight route of an observation. Apr 19, 2016 · Hello, I have a few different graphs which I would like to display in one. Dec 27, 2018 · Hello William, I am testing different ways to merge two datasets, when I use joinby there are a duplicate of data, when I use merge by two variables I receive a message saying: variables country year do not uniquely identify observations in the using data, and I dont know what does it mean. g Aug 14, 2024 · In short, we use fuzzy merge when the strings of the key variables in two datasets do not match exactly. The reshape command Combine two datasets with the same type of observations - merge 1:1 ¶ We start with the simplest type: when we have the same type of observations in both datasets, and want to add mode variables. Another helpful function is the addplot function, however it is not working out for me. multihistogram allows Stata users to easily construct overlaid histograms with aligned bins in Stata. gen county=state+string (number,"%02. gen county=state+number If it's numeric, use the string function with a format . Add new observations to already existing variables using append. By join we mean to form all pairwise combinations. Learn how to combine data seamlessly for comprehensive analysis and insights. dta append using yearly2. string variables or more generally expressions which are or which evaluate to strings) on either side. This video demonstrates how to merge files into a single dataset in Stata using the *merge* command. One-to-one merge: merge 1:1 In the dataset we just appended (got3), we have 5 variables, with the id variable uniquely identifying the 6 observations in the data. Learning Outcomes Add new variables to an existing data set using merge. While append added observations to a master dataset, the general purpose of merge is to add variables to existing observations. Abstract. It’s roughly equivalent to merge when the files are on disk. There are two commands to merge data i. Description merge joins corresponding observations from the dataset currently in memory (called the master dataset) with those from filename. Aug 13, 2020 · APPEND Append is a STATA command that you should use when you want to ‘stack’ two or more files so they come ‘on top’ of each other. It still sounds like 1:1 merge s. Below, we will draw a dataset as a box where, in the box, the variables go across and the observations go down. In SPSS I understand I would probably perform the last stage with: COMPUTE HomeAccess=MEAN. Follow-Ups: Re: st: Re: Combining multiple observations into one observation with multiple variables From: Conor Hughes <cbhughes@uchicago. Think about all the countries in the European Union, or all children in a school. Discover efficient techniques for merging datasets in Stata. In addition, we are often interested in combining multiple observations from some unit of analysis (like countries or states or people) to create a panel data set. In this video, we explained how to merge data in stata. Combining datasets 22 Combining datasets You have two datasets that you wish to combine. Oct 3, 2017 · Hi all, I have many csv files that have one common variable (date) and one other variable. I would like to merge the two datasets using the only available option: the name of the firms in the two datasets. You can change this assumption by using the update and/or replace options to use the using values. My task is to merge this data without manually changing anything in them. First, load one of the les into Stata, then append the second: use yearly1. When the number of variables in a dataset to be analyzed with Stata is larger than 2,047 (likely with large surveys), the dataset is divided into several segments, each saved as a Stata dataset (. Here, "name-of-second-dataset" (called the "using dataset" by the Stata people) is merged to the data in memory (called the "master dataset"), assuming that each value of variable "caseid" is present only once in each of the data sets. dta and two. This handout reviews using the most valuable command for managing multiple data sets, the merge command. I have two string variables. Remember to use the merge command, specify the merge variables, and analyze the merged data using various Stata commands. merge 1:1 personid using In that discussion, each observation in the dataset could be uniquely identified on the basis of a single variable. Therefore I would like to generate a variable combining two string variables (Origin and destination). Jul 11, 2024 · A guide to using Stata for data workHere's what you must know about the two datasets you are about to merge. Can somebody guide me on how to merge the two dataset? I am posting the sample of the data below. We would like to show you a description here but the site won’t allow us. I would like to generate a new variable that is also a yes/no variable, and it is only categorized as a yes if the response is yes in both of the original variables. We use either reclink or matchit commands of Stata to conduct fuzzy merge. I want to combine all of the observations that share an id and a date in such a way that if at least observation has a value of "1" in a dummy variable, the combined variable will also have a value of "1" in that dummy. I would like to import them all to dta files and then merge them horizontally using the date variable. edu> References: st: Combining multiple observations into one observation with multiple variables From: Conor Hughes <cbhughes@uchicago. Values of numeric variables are converted to string, as is, or converted using a format under option format (%fmt) or decoded under option decode, in which case maxlength () may also be used to control the maximum label length used. Stata can also join observations from two datasets into one; see [D] merge. Merging two datasets require that both have at least one variable in common (either string or numeric). Jul 31, 2018 · I am trying to "combine" two categorical variables in Stata (say var1 and var2) into a new (also categorical) variable (say res). How do I merge these to tables to get a table of the columns: Location, X, Y when the identifiers have a different name? The merge command combines data sets by combining observations that have the same value of an identifier variable or variables, so the result has all the variables from both files. Most of the projects done in 17. Since there is an overlap here in terms of the values that the variables can take, I have recoded Description merge joins corresponding observations from the dataset currently in memory (called the master dataset) with those from filename. Dataset 1: Data Set 2: Jan 30, 2023 · I have a dataset in Stata where one observation is spread out over multiple rows like the table below. Setting aside the impending -merge- or -append-, some extra comments are yet possible: 1. I have created an example of what I am looking for below (see attached file). Both have a unique identifier. We will call these “overlapping” variables. dta files, it is necessary to merge the What's happening is you merge dataset 2 to dataset 1 and it creates a variable called _merge describing what merged and why. What is the identifier variable on which the files should be combined? Is each observation (row) of the identifier variable unique? In other words, does each row value for the identifier variable occur only once? The answer to this question matters for how you would merge the two Mar 30, 2017 · Combine two string variables into one, such that both a + b and b + a become ab 30 Mar 2017, 03:36 Hello, I am currently aiming to create an identification variable in order to identify the flight route of an observation. In Merging data, part 1, I discussed single-key merges such as . Default Stata allows users to construct overlaid histograms using the -twoway- graph command. With practice, you will become proficient in merging data This includes hotlinks to the Stata Graphics Manual available over the web and from within Stata by typing help graph. I've used the following to try and create individual files, but for some reason some of the files are read as 1 var, and some as 2 var. Doing it as a problem in arithmetic (multiplying one numeric id by an Oct 17, 2021 · Hello everyone! I'm a very beginner using STATA so please I'd like to get some help with merge command, My purpose is to add variables to the master dataset and keep only what is matched related to a particular observation, so I've been told I must use merge command (I'm using merge in STATA 17). Sep 25, 2017 · If you want two variables with 11000 observations to be put into one with 22000 observations, then as Clyde already indicated the solution is either stack or reshape. 1 Introduction to merge and append Often when we are working with data sets it is necessary to merge or append existing data to other data sets The merge command combines the dataset in memory, known as the master dataset, with a dataset on disk, known as the using dataset. I found the command -matchit- and tried it with its Jan 4, 2022 · Level up your Stata Frame Game. Mar 7, 2025 · Data merging, a fundamental operation in data science and statistical analysis, allows the integration of information from disparate datasets into a unified structure. The merge command combines data sets by combining observations that have the same value of an identifier variable or variables, so the result has all the variables from both files. My master dataset has more observations than my using dataset, but they both have in common two Description joinby joins, within groups formed by varlist, observations of the dataset in memory with filename, a Stata-format dataset. filename is required to be sorted by varlist. gen newcity = province_str + city_str > Third, translate -newcity- into a numerical variable by command -destring-. The files should have identical or similar variables (columns) but different in terms of content that is in the rows of the files. comCopyright 2011-2019 StataCorp LLC. Then it tries to merge 3 to 1+2 and create that same variable and can't because it already exists. Say we have another data file containing the id variable and the same 6 observations, but with a new variable (or column) called status. The example below illustrates what I am trying to achieve: If the using data set adds more variables to the master data set and observations represent the same things in both data sets, then this is a job for a one-to-one merge. 7l4ts d65jgcw ntux4 e27p 4h 1n ijwlr vbx5lht iqykex eae7shyp