collapse with if condition

[Luisa Opitz]

Hi, I have the following collapse function:
collapse (mean) mean_BARTAdj=BARTAdj (sd) sd_BARTAdj=BARTAdj (count) n=BARTAdj, by(weekday)
which works just fine. Now, I would like to add a condition. I have another variable sense. If sense >=3 I would like to create a mean, sd and n and if sense <3, I would like to create mean, sd and n.
Thank you very much!

[Andrew Musau]

You can use the -group()- function of egen to combine variables. In this way, you can get the breakdown that you want.

sysuse auto, clear
gen goodcond= rep78>3
lab def condition 0 "fair condition" 1 "good condition"
lab values goodcond condition
egen origin_condition= group(foreign goodcond), label
collapse mpg weight turn, by(origin_condition)

Res.:

. l

     +-------------------------------------------------------+
     |        origin_condition       mpg    weight      turn |
     |-------------------------------------------------------|
  1. | Domestic fair condition   19.1351   3,404.6    42.027 |
  2. | Domestic good condition   21.5333   3,101.3        40 |
  3. |  Foreign fair condition   23.3333     2,010   35.3333 |
  4. |  Foreign good condition        25   2,364.2   35.4211 |
     +-------------------------------------------------------+