Can you create lists in Stata?
Can you create lists in Stata?
When you initialize the use of variable lists, Stata will automatically create four variable lists, called the “System variable lists”. Every numeric variable in the current data set is automatically placed into one of these four lists: vlcategorical : Variables which Stata thinks are categorical.
What does the LIST command in Stata do?
list, typed by itself, lists all the observations and variables in the dataset. If you specify varlist, only those variables are listed. Specifying one or both of in range and if exp limits the observations listed.
How do I create a global variable in Stata?
A number of things have to be noted: 1) The name of a global can be up to (and including) 32 characters long, but it may be as short as a single character. Be sure to use the correct single quotation marks: The accent grave, or gravis, at the beginning, and the apostrophe at the end.
What is Strpos in Stata?
Description. strpos(haystack, needle) returns the location of the first occurrence of needle in haystack, 0 if needle does not occur, or 1 if needle is empty. strrpos(haystack, needle) returns the location of the last occurrence of needle in haystack, 0 if needle does not occur, or 1 if needle is empty.
How many variables are in a dataset Stata?
2,047 variables
There’s a limit of 2,047 variables in Stata/IC, 32,767 in Stata/SE, and 120,000 in Stata/MP. You can have as many observations as your computer’s memory will allow, provided you don’t go too far above 2 billion cases with Stata/SE and 1 trillion with Stata/MP.
What does == mean in Stata?
The double equals, ==, is used to test for equality. It is sometimes called logical equals because it is part of a logical test that returns either a one (true) or a zero (false).
What does Di mean in Stata?
In Stata these are called respectively _N and _n. For more see this entry on the ATS website. There is however one exception: _n within the display command (often abbreviated as di) means: “display a new line” instead of “current observation number”.
What are global variables in Stata?
In Stata, a global macro is something that is stored in memory and can be used anytime during a Stata session by reference to its name (a local macro differs basically inasmuch it can be used only within a circumscribed piece of a program or a do-file).
Which is an example of an expression in Stata?
An expression is a formula made up of constants, existing variables, operators, and functions. Some examples of expressions (using variables from the auto dataset) would be 2 + price, weight^2 or sqrt(gear ratio).
What’s the difference between generate and replace in Stata?
Whereas generate is used to create new variables, replace is the command used for existing variables. Stata uses two different commands to prevent you from accidentally modifying your data. The replace command cannot be abbreviated. Stata generally requires you to spell out completely any command that can alter your existing data.
What to do if there are missing values in Stata?
If missing values are generated, the number of missing values in newvar is always reported. If Stata says nothing about missing values, then no missing values were generated. You can use generate to set the storage type of the new variable as it is generated. You might
Why does Stata use a placeholder for a real value?
This is because Stata uses the r (…) as a placeholder for a real value. For another example of this, say that we want to calculate the variance of read from its standard deviation (ignoring the fact that summarize returns the variance in r (Var) ). We can do this on the fly using the display command as a calculator.
