stata create matrix from variables

webuse auto.dta We do so by summing up the two existing variables: poplt5 (population < 5 years old) and pop5_17 (population of 5 to 17 years old). If you are not happy with the original variable name of total population, you can change it by using the -rename- command. As for the variable subscripting, I'm afraid you can refer to one observation only. If you dont wont to replace your existing work, use this command instead Asking for help, clarification, or responding to other answers. How is Jesus God when he sits at the right hand of the true God? X=st_data(.,.) Thank you, I'll try the code and see help at the same time. If you provide more information about your question, you may be able to elicit a more complete answer. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. S Plus, Matlab, etc.) where $B$ is of dimension rows=2 and columns=3. mata drop X f g, Stata offers three functions useful for checking conformability conditions. Here we create the youth population variable again, but this time we make it into thousands and replace the one we just created. If you also want the frequency counts, you can use the . Here we create another new variable called pop_c2 then do the recode in the same manner as we did for pop_c. so long as your matrix of independent variables has 1000 rows. b, Suppose you have the matrices A to D defined as Not sure if it was just me or something she sent to the whole team. The function A very useful way to save your results is have stata automatically put everything in a log file. Is it illegal to use resources in a university lab to prove a concept could work (to ultimately use to create a startup)? For matrices A and B of same dimensions, matrix addition is given by /Filter /FlateDecode is, $$ X=(ones=J(1000, 1, 1),x) to load data into mata. If you prefer to do you work in other mathematical packages (e.g. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, How to generate a random alpha-numeric string. xZIoWJ v&deMYz%|fK0&^{+*1^H%DvuYiz"jpXV]6eEE$rq#^oW.qQpJ2rsC,Gp,:{{6,*v0x`%sT3eI%]tZ;[T?dm/ed*o'z~gvGN_;uHJ =JDw# ]+DQ)]^ColSZ+_%+s6Hr8c#r/*;W2 )KQO~%/lnV7v:SUzU9qJb1E)xp ,?MpGPf0 f=(1,2,3) clear set obs 10 matrix M = J (10, 10, .) These are easy. To fill it element by element use Thanks for contributing an answer to Stack Overflow! To Stata, a matrix is a named entity containing an r c (0 < r matsize, 0 < c matsize) rectangular array of double-precision numbers (including missing values) that is bordered by a row and a column of names. Then we create a new variable called pop_c and transform the original variable pop into three categories. where command is some stata command. Once you have loaded data into stata (.dta or .csv files), it is easy to access that information from within mata. Code: matrix mat1 = J (8,8,.) \begin{equation} To load this file into stata, issue the command \end{equation} Was the ZX Spectrum used for number crunching? Now, I want to create a 11x14 matrix (data set) and the value of the matrix is r_output. Is it correct to say "The glue on the back of the sticker is dying down so I can not stick the sticker to the wall"? Any disadvantages of saddle valve for appliance water line? What properties should my fictional HEAT rounds have to punch through heavy armor and ERA? First, xtset your data - you're telling Stata what variable uniquely identifies the "panels" since your long data form has repeated rows. Why is the federal judiciary of the United States divided into circuits? 12 Mar 2015, 11:15. You will need an extra step to put data from a variable into a matrix, using mkmat. Suppose you have the file mroz.dta on your personal computer in a directory called /some/place. Of course, combinations of these operators are possible as well. I want to make a sample of two variables, according to a specific probability distribution. Say if we want to break pop (total population) into three categories. command from the stata command line. 1. a local macro with an ID. egen V = seq (), f (1) t (10) mkmat V in 1/10 // Put observations 1 to 10 from variable V into matrix V matrix M [1,1] = V // Replace . Here we rename pop as pop_t. It is also possible to copy in only a subset of rows and columns as --- On Wed, 9/3/11, Chen, Xianwen wrote: > The first question is a fast way to create a n x n matrix. Here we'll: Load the sysuse auto dataset. rows(X) and cols(X) return the number of rows and columns of X respectively, while $1,2,3,\ldots,99,100$). Code: matrix mat1 = J (5,2) offers two arguments to the function, but not three as are required. These are easily accessed from within stata. The first row of this new matrix is values of r_output of province code 01 in sector order: SA, SB, SC, SD, SE, SF, SG, SH, SK, SL, SM, SN, SO, SP). I would like to label them so that other people can get a better idea of what they are. %PDF-1.5 I will illustrate their use early in the class. Stata datasets in Mata. Why do we use perturbative series if they don't converge? This command can be combined with what we have previously to create the fully matrix of independent variables (with the constant in the first positions) using Books that explain fundamental chess concepts, Irreducible representations of a product of two groups, Can i put a b-link on a standard mount rear derailleur to fit my direct mount frame. Please edit your question to show Stata code, or ask a new question. Here is one way to create the matrix in your matrix () command: matrix input p = (0.04,0.1,0,0.06 \ 0.05,0.3,0,0.05 \ 0.14,0.1,0.06,0.1) This answers the question in the title of your post. If you provide more information about your question, you may be able to elicit a more complete answer. for example You will need an extra step to put data from a variable into a matrix, using mkmat. 3&4&1&2&3 \\ Find centralized, trusted content and collaborate around the technologies you use most. \begin{equation}\label{eq:ps1_question} How do I generate a random integer in C#? Unlike Mata, Stata does not allow users to create matrices containing string values. $$. Do files allow you to put all of the relevant stata commands for a project into one file, so that results can be easily replicated from one stata settion to the next. The command Notice, when you type mata from the stata command window, the command prompt changes from a . D=(1,2,3 \ 4,5,6) Should teachers encourage good students to help weaker ones? rev2022.12.11.43106. To delete only a few matrices, vectors, or scalars, issue E=(A,B \ C,D) The command I(1000) will create an identity matrix with 1000 rows. Will create (or if it exists, will replace) the file my_first.log in the folder /some/place. (for mac/unix and the data will be loaded. \begin{bmatrix} > For example, to create a 8 x 8 matrix for later data > manipulation. First we use the -tabulate- command to see the frequencies of this variable. In contrast. B[2,3]=10 However, it seems JavaScript is either disabled or not supported by your browser. gen old=1 if age>=60 Can several CRTs be wired in parallel to one oscilloscope circuit? You got a good answer, but a better question would show some attempt at code in the language you're asking about. Save the r (table) matrix for each regression to a custom named matrix. Otherwise Stack Overflow would be swamped with questions of the form: What is the code for task X in language Y? You can do this using conditional statements 3&4&8&9&10 \\ We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. Default is to just display probabilities. Not the answer you're looking for? mata Is there a higher analog of "category with all same side inverses is a groupoid"? X=st_data((1::5,7::9),("mpg","rep78","weight")) For windows, if the file is in a directory \some\place, simply reverse the slash characters. Then, I use matrix rownames to label the rows of cellcounts with the labels stored sexlabels. stream 22 0 obj << B[1,2]=6 The command Why does the USA not have a constitutional court? g=(3\ 4 \5) Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. We do so by summing up the two existing variables: poplt5 (population < 5 years old) and pop5_17 (population of 5 to 17 years old). \begin{equation} First, sex is stored as a numeric variable, so I can use decode to create a string variable called sex_s. 1 I want to insert all the variable values into the first column of the matrix. Here we use the -generate- command to create a new variable representing population younger than 18 years old. view search reg. The command I am using the command -pco- in Stata 12. A=(1,2 \ 3,4) For a given row, columns are added to the . Making statements based on opinion; back them up with references or personal experience. For example, suppose you want to use the file mroz.dta that is used in the first problem set. Now that we have some new variables created or recoded from original variables. Consider a two by two matrix, How do I generate random integers within a specific range in Java? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. \end{equation} Beware of missing value warning messages. Conditional commands are also possible. To see the same set of results in a better help viewer, type To display your matrix, type Notice that the correlation along the diagonals of the table are each 1.0000, since each variable is perfectly correlated with itself. end B[2,1]=8 Irreducible representations of a product of two groups, ST_Tesselate on PolyhedralSurface is invalid : Polygon 0 is invalid: points don't lie in the same plane (and Is_Planar() only applies to polygons). We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. copies the entire currently loaded stata database into mata, while Then, we will confirm that . To see the same set of results in a better help viewer, type \begin{bmatrix} 1&2&5&6&7 \\ Stata has a linear algebra environment that can be started using the A=(1,2 \ 3,4) 3 & 4 id=(1::100) I(1000) The st_view command has identical syntax to st_data and will allow for changes to be preserved once back in stata. Find centralized, trusted content and collaborate around the technologies you use most. mata For example, here is how to create a correlation matrix for just . Arbitrary shape cut into triangles and packed into rectangle of the same area. sample_100 = rDiscrete(n=50000,pf=p) Next, I use levelsof to store the levels of sex_s to the local macro sexlabels. Books that explain fundamental chess concepts, Counterexamples to differentiation under integral sign, revisited. How can I generate random alphanumeric strings? 14.1.1 Denition of a matrix Stata's denition of a matrix includes a few details that go beyond the mathematics. Other software packages are arguably more adept for these tasks, but in this class well focus on stata as the tool for all of our work. in Stata creates a matrix with 8 rows and 8 columns and missing as every entry. (for mac/unix and the data will be loaded. Would be the OLS estimator we discuss in Chapter 1. MOSFET is getting very hot at high frequency PWM, Central limit theorem replacing radical n with n, PSE Advent Calendar 2022 (Day 11): The other side of Christmas, Exchange operator with position and momentum, confusion between a half wave and a centre tapped full wave rectifier. The command is 2. tab x, gen(dum_x), Sometimes, you want to get rid of all the variables for a new analysis, or simply to start over. This post demonstrates how to create new variables, recode existing variables and label variables and values of variables. Once a variable is created, it can be modified using the command help mata command The matrix $E=\begin{bmatrix}A & B \\ C & D \end{bmatrix}$ I personally believe this is good practice even if you are the only person using the dataset we forget things, the labels can serve as basic documentation of the dataset. How can I fix this? Asking for help, clarification, or responding to other answers. search keyword You will then have the file loaded into stata. Here I briefly introduce the use of matrix algebra manipulations and maximum likelihood programming in Stata. C=A*B Connect and share knowledge within a single location that is structured and easy to search. Commands for mata may also be nested inside of stata do files (command files) so long as all mata commands are between the commands I want to calculate the euclidean distance between subjects (n) based on three attributes (x y z). That's not going to work. To create categorical (dummy) variables for each value, use As I mentioned: help matrix will give you the . To subscribe to this RSS feed, copy and paste this URL into your RSS reader. id=(1:100) B[1,1]=5 Yun Tai Why doesn't Stockfish announce when it solved a position as a book draw similar to how it announces a forced mate? Zorn's lemma: old friend or historical relic? We'll specifically call them "row1", "row2", and "row3". % will give you, $$ This is really your only way of distinguishing if you are in the mata or stata environment. Ready to optimize your JavaScript with Rust? \end{bmatrix} search mata keyword Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. copies the all rows and only the three variables listed (columns) into X. \end{bmatrix} Why do some airports shuffle connecting passengers through security again, Received a 'behavior reminder' from manager. Inserting variable's values into a matrix - Stata. [8kbAKx|LW4 4#:@y-M'2BqN*r$Tn? g10hYEZ1T?,. You can also do keyword searches Error in attempting to assign values to a matrix in R, How to create a two dimensional matrix on Stata. Calculates the total number of elements in matrix X, equal to (# rows) $\times$ (# columns.). For example, \end{bmatrix} We use variables of the census.dta data come with Stata as examples.-generate-: create variables. Remember, once you end the mata session, all changes to the data following an st_data command are lost. so long as your matrix of independent variables has 1000 rows. B=J(2,3,.) By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. So a newly created subsequent column (e.g, id_1) has a subsequent (i+1) value of the original variable (e.g., id ), and so on. and view search keyword Multiplication (assuming conformability of A and B) is given by Here is one way to create the matrix in your matrix() command: This answers the question in the title of your post. gen ln_gdp=log(gdp) I thought of making a matrix that expresses the probability distribution but my code results in "p is not defined". Suppose you have data set containing the variable names "gdp" and "income" Then mkmat gdp income, mat(X) will create a matrix X with all the values for gdp from the data set in the 1st column and values for income in the 2nd To . will generate the natural log of gdp for each row in your dataset. 1 & 2 \\ mata describe JavaScript must be enabled in order for you to use our website. Dear Stata users, I have some trouble in creating a new variable as a result of a matrix. You can also do keyword searches How to randomize (shuffle) a JavaScript array? If you need to find general help in stata, type QGIS Atlas print composer - Several raster in the same layout. X=st_data(.,.) By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. There are generally two ways to get your .dta stata data into mata. For all of our class excercises, we will be using datasets on my website. C=A+B Thus, the half bottom of the matrix gets missing (the upper table: ///) . followed by To load this file into stata, issue the command Assuming that you are trying to use Stata, you are giving us an error message, but no code. To learn more, see our tips on writing great answers. When would I give a checkpoint to my D&D party that they can return to if they die? where command is some mata command. B[2,2]=9 View the entire collection of UVA Library StatLab articles. In step two, each local . replace ln_gdp=ln_gdp+1 for example The use of do files are highly recommended for your own work, and are a required part of your assignments in the course. // To do this, use the Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. Lets label them as low, medium and high. We recommend that practitioners store each row of a string matrix in a separate local. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. To initialize a log file and use it, issue $$, Row and column vectors can also be created using the same basic syntax: ones=J(1000, 1, 1) matrix foo = J(8,8,.) To load this file, issue the command CLIR Postdoctoral Fellow copies in rows 1 to 4 and 7 to 9 with the three variables into X. X\.&xUTvtunLrFjVJAe=N!Vl1: ^d F/:!LH=usKjjbS;L! I'm struggling with "subsetting" both the variable and the matrix. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, Performing Stata dummy matrix expansion xi in R using model.matrix, Stata access element of matrix as scalar or macro, Splitting a string variable in Stata, and placing values in order, Return stored results with svy and tab command in Stata, Extract Stata matrix element by column name. Hence it is illegal. Arbitrary shape cut into triangles and packed into rectangle of the same area. Use the -matrix- command to copy the contents of the r (table) to a custom matrix. We use variables of the census.dta data come with Stata as examples. Here we use the -generate- command to create a new variable representing population younger than 18 years old. For windows, if the file is in a directory \some\place, simply reverse the slash characters. Similarly, the second row is for province 02 and so on until province code 17. log using "/some/place/my_first.log", append txt to close the file and save all changes. Matrix Commands in Stata Stata's matrix commands are very easy (and can always be referenced in the . >> The -pco- command reduces all attributes to two dimensions, and generates a matrix (n x n . B=(5,6,7 \ 8,9,10) If you need to do all your work in mata and dont need to change any of the underlying .dta data, I recommend the copy method. insheet "/some/place/mroz.csv" length(X) > The second question is regarding variables. This creates a 8x8 matrix containing all missing values (.). invsym(x'x)*x'y Then we can use xttrans <var> for our transition probabilities. or, a column vector can be created by use "/some/place/mroz" How does legislative oversight work in Switzerland when there is technically no "opposition" in parliament? are useful for constructing row and column vectors, respectively of incremented integer values between 1 and 100 (e.g. Once you have finished using mata you can return to the normal stata environment by typing We can use the -recode- command to recode variables as well. B[1,3]=7 and 5&6&4&5&6 You can also create a correlation matrix for only a certain subset of variables in a dataset by specifying the variables after the corr command. X=st_data(.,("mpg","rep78","weight")) will list all the matrices, vectors, and scalars currently defined. mata clear To learn more, see our tips on writing great answers. // /Length 2647 Connect and share knowledge within a single location that is structured and easy to search. webuse set http://rlhick.people.wm.edu/econ407/data/ Suppose you have the file mroz.csv on your personal computer in a directory called /some/place. followed by If the expression on the right evaluates to a matrix (not a scalar), this will replace the submatrix with the top left element given, so only the the top left element on the left side of the equation will be enough. Subtraction follows in a similar way. Why does Cauchy's equation for refractive index contain only even power terms? Suppose you want to create a dummy called old =1 only if age is greater than 60 and otherwise zero. However, the following command works only until the n-th row is reached to get a value; then the subsequent new rows become empty. Suppose we have 1000 observations and we wish to create a column of ones (this is especially useful for estimating a constant term), use this command This section is an abbreviated version of an excellent stata tutorial by Kurt Schmidheiny at the Universitat Pompeu Fabra, Barcelona Spain, A Brief Stata Primer, with Mata and Linear Algebra, Loading stata files stored on your hard disk, Loading text files stored on your hard disk, Getting Information about your matrices and vectors, Multiplication of Matrices if missing elements. The special commands As I mentioned: help matrix will give you the documentation, which will help you. log using "/some/place/my_first.log", replace txt you are free to do so. view search mata inverse, There are two ways to create a matrix. Making statements based on opinion; back them up with references or personal experience. u=3. clear command. When you are finished for a stata session, issue the command Run three regressions, one for each row, and. For example, suppose we use the stata sample dataset, auto.dta accessed by My files are read-only, so if you plan on making changes, you should immediately save these locally so your changes to the data persist through time. Why is MATLAB so fast in matrix multiplication? Was the ZX Spectrum used for number crunching? For this example, it would be "xtset id". How do we know the true value of a parameter, in order to check estimator properties? You may then open it using the text editor of your choosing. Once you have loaded data into stata (.dta or .csv files), it is easy to access that information from within mata. In this course, it is sufficient to use the command $$, Or, you could create an empty matrix of the desired dimension replace old=0 if age<60, Suppose a variable x takes on the values 1,2, or 3. to yield, $$ Thanks for contributing an answer to Stack Overflow! help command Simply define a scalar by Does aliquot matter for final concentration? Views are useful if you want to modify the data in mata and then return to stata with the original dataset changed based on operations in mata, while copying the data is both faster and requires less memory. How do we know the true value of a parameter, in order to check estimator properties? rev2022.12.11.43106. 1 & 2 & 3 As for the variable subscripting, I'm afraid you can refer to one observation only. view search mata keyword log close I generated a 10x10 matrix, and a 10-observation variable (its values don't matter). \end{equation} 1A typical string matrix usually contains variable names, values or labels. I could omit this step if sex was stored as a string variable. will create an identity matrix with 1000 rows. Ready to optimize your JavaScript with Rust? To delete all of these, issue can be constructed by One can copy the data or one can create a view that always refers back to the original stata dataset. p = matrix(c(0.04,0.1,0,0.06,0.05,0.3,0,0.05,0.14,0.1,0.06,0.1), nrow=3, ncol=4, byrow = TRUE) end, If you need to find general help on mata, type \begin{bmatrix} And all of your results will be appended to the log file. webuse mroz How can I randomly select an item from a list? Looks to me as if you are using R or R-like syntax in Stata. to :. matrix mkmat Convert variables to matrix and vice versa 5 svmat Example 2 Let's get the vector of coefcients from a regression and use svmat to save the vector as a new variable, save the dataset, load the dataset back into memory, use mkmat to create a vector from the variable, and nally, use matname to rename the columns of the row . Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. There are many more functions and tools in the mata environment that I wont describe here, but that are accessible to interested students. University of Virginia Library, 2022 by the Rector and Visitors of the University of Virginia. Not the answer you're looking for? C=(3,4 \ 5,6) Creating the Identity Matrix. 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