Reducing data set

[Euslaner]

Is there a way to exclude cases from a dataset if they do not have sufficient observations?

I wrote:

keep house if _n(VCF0900c >= 45)

but it didn't work Is there a solution to this problem? Thanks for any help.

[Leonardo Guizzetti]

I think you've been offered this specific advice recently, but see -help keep- and -help drop-. They have two, mutually exclusive syntactical forms, as is clearly explained.

keep if ....  // filter records and note no varlist
keep varlist // keep only specified variables in varlist, note no if condition

Second your syntax is invalid, so this looks like maybe some AI hallucination.

_n(...)

is not valid. If you want to keep groups defined by variable VCF0900c, which have at least 45 records, here is one possible solution.

bysort _VCF0900c : keep if _N>=45