use using + in range

[Luis Pecht]

Hi Statalist members,

Is "use using" limited to the last observation ? I was expecting to recovery only my last 5 observations, without needing to load my large dataset entirely in memory.

. clear

. use auto.dta
(1978 automobile data)

. list make in -5/l

     +-------------+
     | make        |
     |-------------|
 70. | VW Dasher   |
 71. | VW Diesel   |
 72. | VW Rabbit   |
 73. | VW Scirocco |
 74. | Volvo 260   |
     +-------------+

. clear

. use make in l using auto.dta
(1978 automobile data)

. list

     +-----------+
     | make      |
     |-----------|
  1. | Volvo 260 |
     +-----------+

. clear

. use make in -5/l using auto.dta
'-5' invalid observation number
r(198);

any clue?

[Clyde Schechter]

Your expectations were correct and Stata's behavior here is not consistent with the documentation. -in -5/l- is a valid -in-range and should be acceptable to the -use- command in this context. I have verified that the same error occurs in my setup (version 17MP4, Windows 10). I suggest you notify Tech Support--it looks like you have stumbled on a bug.

In the meantime, you can do this as a workaround:

des using auto.dta
local cutoff = r(N) - 4
use make in `cutoff'/l using auto.dta

[Luis Pecht]

Ok, Clyde I will proceed notifying Tech Support. Meanwhile I confirm your solution does the trick.

thks,

. clear

. des using auto.dta


. local cutoff = r(N) - 4

. use make in `cutoff'/l using auto.dta
(1978 automobile data)

. list

     +-------------+
     | make        |
     |-------------|
  1. | VW Dasher   |
  2. | VW Diesel   |
  3. | VW Rabbit   |
  4. | VW Scirocco |
  5. | Volvo 260   |
     +-------------+