Re: st: Unreasonable error "Obs. nos. out of range"

[Nick Cox <njcoxstata@gmail.com>]

Difficult to comment given this little information, but

0. It is possible to have variables defined but no observations.

1. Possibly more to the point, the -replace- will certainly fail if _N
< 2 but it's not necessarily an error otherwise to refer to -cats[2]-
when it doesn't exist. If -cats- exists as a variable then any
references to subscripts that don't correspond to observation numbers
are interpreted as missing.

2. However, your code does imply that -cats[2]- is being treated as
zero. Could you confirm that -local bak- is not defined before the
code you cite?

Either way, -list-ing the data would make your situation clearer.

This example bears on #1.

clear
set obs 1
gen cats = 1
if cats[2] == 0 {
      di "problem 1"
}
else di "problem 2"

Nick
njcoxstata@gmail.com


On 17 June 2013 15:21, Stefan Bernhard <stefanbernhard88@gmail.com> wrote:
> dear statalisters,
>
> i have a piece of looping code over different variables and all
> observations, and an excerpt of the trace shows this:
>
> = if cats[2] == 0 {
>   local bak = 0
>   }
> - noi di as text "bak is `bak'"
> = noi di as text "bak is 0"
> bak is 0
> - replace `var' = 1 in `i'
> = replace cats = 1 in 2
> Obs. nos. out of range
>
>
> This makes no sense at all to me.
>
> In the first line, it successfully uses the value of cats of
> observations number 2 to define the local bak as 0.
>
> Few lines later, it acts as if there was no more observations number 2
> and cannot replace the number of cats with 1 in observation number 2.
>
> Why does it say Obs. nos. out of range ?
>
> regards, stefan bernhard,
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