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

[Stefan Bernhard <stefanbernhard88@gmail.com>]

1. bak was defined during the first loop on observation 1 and thus was
still 0 after that :/

myvar[0] and myvar[_N+1] could be exempt from the error listing and so
one would know if anything between those one refers to is not there...

regards, stefan bernhard,

2013/6/17 Nick Cox <njcoxstata@gmail.com>:
> You have not answered all my questions about your code.
>
> I don't know what your programming criteria are here.
>
> I note only as one common example that references to [_n-1] and [_n+1]
> are commonplace and deliberate.
> I don't want to see error messages that myvar[0] and myvar[_N+1] don't
> exist. I know that already.
> Nick
> njcoxstata@gmail.com
>
>
> On 17 June 2013 17:36, Stefan Bernhard <stefanbernhard88@gmail.com> wrote:
>> Thx Nick, so the thing ist that it is actually possible to refer to a
>> non-existant observation, which caused the confusion.
>>
>> I then found the error after I knew that the observations had to be
>> diasspearing.
>>
>> But I think the way this is handled is somewhat awkward. It should
>> already tell me that there is no 2nd observation when I try to refer
>> to it with the if clause :/
>>
>> best regards, stefan bernhard,
>>
>>
>>
>> 2013/6/17 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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