# Can you Undrop a variable in Stata?

## Can you Undrop a variable in Stata?

Warning: drop and keep are not reversible. Once you have eliminated observations, you cannot read them back in again. You would need to go back to the original dataset and read it in again. Instead of applying drop or keep for a subset analysis, consider using if or in to select subsets temporarily.

## What is cross tabulation in Stata?

Cross Tabulation. A crosstabulation or a contingency table shows the relationship between two or more variables by recording the frequency of observations that have multiple characteristics. Crosstabulation tables show us a wealth of information on the relationship between the included variables.

Can you tabulate multiple variables in Stata?

In multiway tabulations, you can display frequencies across levels of two or more variables. You can have levels of one variable nested within levels of another variable in columns, in rows, or in both dimensions.

### How do you use preserve command?

When preserve is issued, the user’s data are preserved. The data in memory remain unchanged. When the program or do-file concludes, the user’s data are automatically restored. After a preserve, the programmer can also instruct Stata to restore the data now with the restore command.

### How do I run a command in Stata?

To execute all the commands in your do file sequentially in Stata, press the “Execute (do)” icon, located in the toolbar of the Do-file Editor window. Alternatively, you can click on Tools in the Do-file Editor window, then on Execute (do).

What is cross tabulation and chi square?

Crosstabulation (Chi-Squared) Introduction. Crosstabulation is a powerful technique that helps you to describe the relationships between categorical (nominal or ordinal) variables. With Crosstabulation, we can produce the following statistics: Observed Counts and Percentages. Expected Counts and Percentages.

#### What does tabulate command do in Stata?

tabulate produces a one-way table of frequency counts. For information on a two-way table of frequency counts along with measures of association, including the common Pearson χ2, the likelihood-ratio χ2, Cramér’s V , Fisher’s exact test, Goodman and Kruskal’s gamma, and Kendall’s τb, see [R] tabulate twoway.

#### What does it mean to 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.