We can use a scalar to store a value defined in a matrix. This command tells Stata to display the value in the first row and third column of matrix ‘d’. If we would like to display a specific value from this matrix, we can specify the row and column that needs to be displayed as follows: display d
Similarly, if we had separated all our numbers with backslashes (and no commas), it would become a column vector with the numbers arranged in one column and six rows. It would then be just a row vector with one row and six columns. If there were no backslash, the matrix would only have one row with the six numbers each in a column. Displaying the matrix through the following command helps us understand how it looks like: matrix list d The backward slash indicates that a new row is to be started.’7,8,9’ will therefore make the second row of the matrix. The first set of three values, separated by commas, ‘4, 5, 6’, make up the first row of the matrix. In this example, ‘d’ is the name of the matrix which can be set to whatever name you find appropriate. To define matrices, we use a syntax slightly different to scalars: matrix define d = (4,5,6\7,8,9) Defining Matrices in StataĪs mentioned above, matrices store multiple values in rows and columns. The display command can also return us the result of operations performed on scalars.
#GEODIST AND GEONEAR STATA PLUS#
This would result in the output ‘’2 plus 2 is equal to 4’’. In order to display two scalars together, we can simply display them together: display c b We can also store strings in scalars by enclosing our string in inverted commas: scalar c = “2 plus 2 is equal to” The displaycommand will return a result of ‘4’. For example, we can also define a scalar as follows: scalar b = 2+2 display b
Scalars can also store the result of an operation as well. ‘var1’ will not have the value of ‘a’, rather it would take on the value represented by this scalar, which is ‘123’. We can also generate a new variable and assign it a value that is already stored in a scalar. GEODIST: Stata module to compute geographical distances. the length of the shortest curve between two points along the surface of a mathematical model of the earth, to significantly reduce the number of distances that must be computed. This will display ‘123’ in the result window in our example. Geonear finds the nearest neighbors using geodetic distances, i.e. In order to display the content that is stored in a scalar that has been defined, we simply use the display command: display a You can replace it with whatever name you find appropriate. In order to define a scalar in Stata, we use the following syntax: scalar a = 123 Matrices, on the other hand, can store multiple numbers or strings. Scalars can be defined as placeholders in Stata that can store a single number or a single piece of string. To illustrate the concepts, we will use Stata’s built in automobile dataset which can be loaded by using the following command: sysuse auto.dta, clear What Are Scalars and Matrices
#GEODIST AND GEONEAR STATA HOW TO#
This article goes over what scalars and matrices are and how to work with them in Stata.
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