The following code will come in handy for this tutorial. The printed stata base reference manual provides systematic information about all stata commands. Gsm getting started with stata for macgsu getting started with stata for unixgsw getting started with stata for windowsu stata users guider stata base reference manual bayes stata bayesian analysis reference manual cm stata choice models reference manual. As for the books, i used scott longs workflow of data analysis using stata and newton and coxs seventysix stata tips. Example 1 we demonstrate the use of pkcollapse with the data described inr pk. This is exactly the procedure described at pag 32 which i am not able to replicate even for the example.
In the sum function and the collapse command, missing values look as if they are. We covered this before, but you will use it a lot with panels. Remarks and examples collapse takes the dataset in memory and creates a new dataset containing summary statistics of the original data. Data management, graphics, users guide, and programming and reference manuals that are categorized by command. Now, i want to know the regional average, but i want to weigh each citys cost share by its population size.
Dear stata listers i am struggling to understand how to implement the example at pag. Iniciando stata stata es una poderosa herramienta en aplicaciones econ omicas. So stata will add up the data for all of the observations, not just those in a given school. Stata press 4905 lakeway drive college station, tx 77845, usa 979. I list are covered in the stata manuals, and some have been discussed in.
Why am i losing precision with large whole numbers such. This is much liking creating statistics for groups of cases, but. We will show an example on how to collapse our daily time series to a monthly time series by making use of a function of this kind. The fun argument to aggregate means you can specify classspecific aggregation functions, so it would be feasible if verbose to produce. It means that i am not able to get weighted average prices paid in my sales data set at a weekproduct level where the weight is the units sold. Get to know statas collapse commandits your new friend. Many stata commands support the in qualifier, but here we need if and the syntax hinges crucially on the fact that under the aegis of by. Even if string variables were allowed, it would not be what you want, e. Then, in stata type edit in the command line to open the data editor.
Running collapse command in stata without losing key. The most direct analogue is aggregate, even though aggregate and collapse work slightly differently. We need to collapse the daily data to monthly data. One common application in stata is the combination of the collapse and merge commands. Reprinted in stata technical bulletin reprints, vol.
Why am i losing precision with large whole numbers such as. Manual copying of results from stata results window remains the most common way many analysts transfer results from stata to word document or excel reports. Collapsing data across observations stata learning modules. We will use this file for showing how to collapse data across observations. For the latest version, open it from the course disk space. Learning these commands is a timeconsuming process but it is not hard. Stata press publisher of books on stata and statistics.
Heres the output for that stata command on the example dataset. Because the syntax diagram for collapse makes using it appear more complicated than it is. I have citylevel data on cost shares and population size. For example, you want to make a new variable and know you can use the assignment statement e. We also highly recommend a sample stata session via the stata web site which gives you a quick overview of using stata as well as seeing the gs getting started manual that accompanied your purchase of stata. Say that you use sas but wish to know how to do a particular command in stata. The printed stata users guide is an introduction into the capabilities and basic concepts of stata. Using multiple statistical outcomes from one collapse can make keeping track of statistic output somewhat difficult by looking at the variable name alone. This course will teach participants how to use stata tabout command for outputting stata results automatically. According to the official manual, stata doesnt do weights with averages in the collapse command p.
Perhaps the most wellknown and important is the by. It is easily replaced with faster code, but the total benefit isnt as great as one would hope. Fortunately, stata develops labels for each variable providing details on which statistic occurred from a collapse. Using the collapse command in stata the analysis factor. For each command, stata provides a description for use, instructions to use which includes options, and examples. Books datasets authors instructors whats new accessibility. This document briefly summarizes stata commands useful in econ4570 econometrics. Entorno del stata otras ventanas a tomar en consideracion son. Data cleaning and management course using stata cesar. U 1 read thisit will help3 the stata documentation consists of the following manuals. Dear statausers, i have panel data for 290 cities belonging to 21 regions. Those are the only readings below without hotlinks. Your data example is difficult to read in any future question do please follow and use dataex for a.
An extra space in the middle of a string is easy to spot. Also see d expand duplicate observations d collapse make dataset of summary statistics d duplicates report, tag, or drop duplicate. Suppose one speculates that test scores depend on the maximum salary a district pays its teachers with a masters degree. If you do not want to collapse, duplicates drop after bysort. Collapse allows you to convert your current data set to a much smaller data set of means, medians, maximums, minimums, count or percentiles your choice of which percentile. Most stata commands and userwritten programs can be used with bootstrap, as long as they follow standard stata syntax. We can use the format command to tell stata that we would like it to display the values with 9 values before the decimal place, and with no values after the decimal, as shown below. Nicks answer is better than mine, and good practice when string data isnt behaving as expected. This tutorial was created using the windows version, but most of the contents applies to the other platforms as. Point the cursor to the first cell, then rightclick, select zpaste. It is also often an excellent treatise of the implemented statistical methods. Instead, it is intended to be a short, simple, sweet and handy reference for spss users who are making the transition to stata.
Stata press, a division of statacorp llc, publishes books, manuals, and journals about stata and general statistics topics for professional researchers of all disciplines. By default, the mean of one or several variables is created. But sometimes it is, and it can become the rate limiting step in a seriously longrunning program. How can i collapse a daily time series to a monthly time. Log file log using memory allocation set mem dofiles doedit openingsaving a stata datafile quick way of finding variables subsetting using conditional if stata color coding system. In this simple form, one would use stata in the following way. Stata is a command driven language there are over 500 different commands and each has a particular syntax required to invoke any of the various options.
Weighted average in statas collapse command stack overflow. This way we can clearly see the values for id and we can see that the id values were not stored properly. Useful stata commands 2019 rensselaer polytechnic institute. Issues collapsing data statalist statalist the stata forum. Stata is available for windows, unix, and mac computers.
The online help in stata describes all stata commands with their. This document briefly summarizes stata commands useful in econ4570 econometrics and econ6570 advanced econometrics. It is helpful to know these functions before we start our task. This is much liking creating statistics for groups of cases, but by collapsing your data a new data set is created that contains these statistics and can be put to further use. Stata supports separate group analyses in various ways. The author no doubt surmised that even if would be used with large datasets, it wouldnt be inside a loop.
Shortly put, i want to run a gmm estimator with a poisson distribution and considering one regressor as endogenous. For each command, stata provides a description for use, instructions to. This column focuses on d statsby, a command that until now has received only passing mention in speaking stata cox 2001, 2003. I couldnt find a stata command on the following issue, so i solved it manually. Append,merge,and collapse instata thisdocumentwillassist stata usersinlearningwhenandhowtouseappend. Collapsing your data means to combine several cases into single lines. Learn how to collapse observations to generate means and standard deviations. Yet this can both be time consuming and errorprone. If the bca option is supplied, command must also work with jackknife.
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