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Re: st: Problem with Stata handling of large dataset
From
Nick Cox <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: Problem with Stata handling of large dataset
Date
Mon, 5 Aug 2013 20:03:46 +0100
The default default [repetition intended] variable type for -generate-
is -float-, which is often inadequate for identifiers, so yes, you
often need to be proactive about variable type.
Prior sorting is needed in the second example.
Nick
[email protected]
On 5 August 2013 19:46, Palan, Stefan ([email protected])
<[email protected]> wrote:
> Hi Scott,
>
> Okay, sorry, that was stupid. Let me describe two different problems I encountered. When I type the following...
>
> clear
> set obs 20000000
> gen id=_n
> tsset id
>
> ...I get an error, since the values of id are not unique. This seems to be an issue having to do with the data type Stata uses for id. If I explicitly define id as type "long", the problem goes away. So I guess I should not rely on Stata to choose the appropriate variable type?
>
> Another point I noticed when testing things. When I type...
>
> clear
> set obs 2
> gen x=_n
> by x: gen y=_n
>
> ...I get an error message that the values in x are not sorted. Do I have to explicitly sort by x prior to running the last command, even if the values in x are already in the correct order?
>
> Stefan.
>
>
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