#STATA COLLAPSE HOW TO#

stat options include mean, median, percentiles, standard deviations, standard errors, first/last values, maximum/minimum etc. From: (Brendan Halpin) Prev by Date: Re: st: limit to number of digits that can be precisely input into a Stata Next by Date: st: score test for the parallel regression assumption Previous by thread: Re: st: Contract/Collapse Combination Next by thread: Re: st: Contract/Collapse. At the end we included one example using function collap() from new package 'collapse'. This data management step can also be done in R using the summaryBy() command in the 'doBy' package. reshape long changes it back to the long format.Д¬ollapse ( stat1) varlist1 ( stat2) varlist2вЂ¦, by( group varlist) aggregates the dataset to summary statistics. For examples of this in Stata, see our Stata Learning Module on collapse. | id semester gpaA attend~A gpaB attend~B |

J variable (2 values) course -> (dropped) reshape wide gpa attendance, i(id semester) j(course) string converts the dataset from long to wide. collapse: makes a dataset of summary data statistics. We covered this before, but you will use it a lot with panels. In the wide format, each column represents variable values of lower levels. year suffix is 98, 99, 00, Stata will put 00 as a year before 99.) A few more useful panel data commands to look up: The by: construction. It is easily replaced with faster code, but the total benefit isn't as great as one would hope. Yet there are also many problems, especially with irregular sets of observations for varying times, that do not yield easily to this approach. But sometimes it is, and it can become the rate limiting step in a seriously long-running program. Counting panels, and more generally groups, is sometimes possible in Stata through a reduction command (e.g., collapse, contract, statsby) that produces a smaller dataset or through a tabulation command. collapse adds meaningful variable labels to the variables in this new dataset. In the long format, variable values of the lower levels are grouped under values of a higher level. The author no doubt surmised that even if would be used with large datasets, it wouldn't be inside a loop. Remarks and examples collapse takes the dataset in memory and creates a new dataset containing summary statistics of the original data. There are more observations in the long format and more variables in the wide format. It seems that the following works, but would also be a lot more time-consuming for my data.Reshape long varlist, i( i) j( j) or reshape wide varlist, i( i) j( j) converts data from long to wide and vice versa. Is there a solution that avoids an additional by operation? If I use (first), then the first error clears, but (count) still fails.

collapse (firstnm) name (count) random, by(mark) commands and operators The collapse command (ctd) If you do not want to collapse. replace mark = mark if missing(mark)Д«ut my collapses fail with type mismatch errors. Macros in Stata are the equivalent of variables in other programming.

#STATA COLLAPSE HOW TO#

I want to collapse on 'mark', which is simple enough with replace and subscripts. It also teaches the participants how to merge and collapse datasets, how to handle string variables, how to generate new variables using the egen command. I have a data set with a lot of strings that I want to collapse, but it seems that in general collapse doesn't place nicely with strings, particularly (firstnm) and (count).

I'm just being lazy here (I don't know how to generate random letters). It isn't necessarily the case that the string variable is destringable. Edit: I should have generated better data.

Stata collapse