What is Egen command in Stata?
The Stata command egen, which stands for extended generation, is used to create variables that require some additional function in order to be generated. Examples of these function include taking the mean, discretizing a continuous variable, and counting how many from a set of variables have missing values.
How do I drop missing values in Stata?
Looking for missing values
- Dropping missing data. Use Stata’s drop command, combined with a logical / conditional statement, to drop missing values.
- drop if important_variable == “”
- drop if important_variable == .
- drop if missing(important_either_kind_of_variable)
- Missing values: Some relevant documentation.
What does group do in Stata?
The groups command for tabulation is built around a call to list. It has no particular limits on the number of identifiers (row, column, or other variables defining cells).
What does byte mean in Stata?
Here we can see that the storage type is listed as “byte.” Byte indicates that the variable is stored as an integer between -127 and 100. The default data storage type for Stata is “float.” By inquiring with Stata using the help command, we see that the float variable type is much larger relative to. byte: .
What is Destring in Stata?
Description. destring converts variables in varlist from string to numeric. If varlist is not specified, destring will attempt to convert all variables in the dataset from string to numeric. Characters listed in ignore() are removed.
What does _n mean in Stata?
observation number
Introduction. Stata has two built-in variables called _n and _N. _n is Stata notation for the current observation number. _N is Stata notation for the total number of observations.
How are missing values handled in Stata procedures?
Summary of how missing values are handled in Stata procedures summarize For each variable, the number of non-missing values are used. tabulation By default, missing values are excluded and percentages are based on the number of non-missing values.
What is an example of a missing value?
For example, 2 + 2 yields 4 2 + . yields . 2 / 2 yields 1 . / 2 yields . 2 * 3 yields 6 2 * . yields . Whenever you add, subtract, multiply, divide, etc., values that involve missing a missing value, the result is missing.
How do you do pairwise deletion in Stata?
Stata also allows for pairwise deletion. Correlations are displayed for the observations that have non-missing values for each pair of variables. This can done using the pwcorr command. We use the obs option to display the number of observation used for each pair.
When to replace missing values by neighboring non missing values?
Users often want to replace missing values by neighboring nonmissing values, particularly when observations occur in some definite order, often (but not always) a time order.
