Re: st: duplicated datetime variable differs from original datetime variable it was derived from

[Milena Przheska <milena.przheska@cosmicdevelopment.com>]

I don't think so.
The original time variable was obtained with the MySQL function
FROM_UNIXTIME() and Stata automatically read it as a double.
The reason I duplicated the variable is so I break ties between events
that had same time stamp, without altering the original data.
Maybe something in this process created the problem, but I did not use
-float- type at all.

On Tue, Nov 12, 2013 at 1:26 PM, Nick Cox <njcoxstata@gmail.com> wrote:
> My guess: you copied a -float- into a -double-. Doing that won't
> restore the precision lost in using a -float- in the first place. It's
> blown away in the wind, washed downriver.
> Nick
> njcoxstata@gmail.com
>
>
> On 12 November 2013 12:01, Milena Przheska
> <milena.przheska@cosmicdevelopment.com> wrote:
>> The problem is that my time1 variable is double, and yet, when using
>> it in the model, it gives that error message
>>
>> On Tue, Nov 12, 2013 at 12:54 PM, Nick Cox <njcoxstata@gmail.com> wrote:
>>> Same answer. Use a -double-.
>>>
>>> Nick
>>> njcoxstata@gmail.com
>>>
>>>
>>> On 12 November 2013 11:51, Milena Przheska
>>> <milena.przheska@cosmicdevelopment.com> wrote:
>>>> When I try to fit a mixed effects model with the time1 variable as
>>>> defined above, I get an error message "time variable must be
>>>> integer-valued".
>>>>
>>>> I do need the time variable to be by the second, otherwise I will have
>>>> duplicate values for the time variable.
>>>>
>>>> If you have any suggestions, I would very much appreciate it.
>>>>
>>>> Thank you,
>>>> Milena
>>>>
>>>> On Tue, Nov 12, 2013 at 12:41 PM, Nick Cox <njcoxstata@gmail.com> wrote:
>>>>> Phil has the answer in one. Unfortunately, you do have to keep
>>>>> remembering that a date-time to Stata is just an integer, usually
>>>>> large, giving time in milliseconds.
>>>>>
>>>>> . di %14.0f clock("07jun2012 03:11:48", "DMYhms")
>>>>>  1654657908000
>>>>>
>>>>> Numbers that big have to be stored as -double-s.
>>>>> Nick
>>>>> njcoxstata@gmail.com
>>>>>
>>>>>
>>>>> On 12 November 2013 11:33, Phil Clayton <philclayton@internode.on.net> wrote:
>>>>>> Dates with times need to be stored in double precision. Try:
>>>>>> gen double time1=time
>>>>>>
>>>>>> See -help datetime-
>>>>>>
>>>>>> Phil
>>>>>>
>>>>>> On 12 Nov 2013, at 10:25 pm, Milena Przheska <milena.przheska@cosmicdevelopment.com> wrote:
>>>>>>
>>>>>>> Dear Statalist members,
>>>>>>>
>>>>>>> When duplicating a time variable by typing
>>>>>>>
>>>>>>> gen time1 =time
>>>>>>>
>>>>>>> the new variable time1 is off by several seconds from the variable time, so
>>>>>>>
>>>>>>> time
>>>>>>> 06jun2012 22:44:51
>>>>>>> 06jun2012 22:44:54
>>>>>>> 06jun2012 22:44:56
>>>>>>> 07jun2012 01:39:58
>>>>>>> 07jun2012 01:40:05
>>>>>>> 07jun2012 01:40:45
>>>>>>> 07jun2012 03:09:48
>>>>>>> 07jun2012 03:09:48
>>>>>>> 07jun2012 03:11:06
>>>>>>>
>>>>>>> becomes
>>>>>>>
>>>>>>> time1
>>>>>>> 06jun2012 22:45:17
>>>>>>> 06jun2012 22:45:17
>>>>>>> 06jun2012 22:45:17
>>>>>>> 07jun2012 01:40:03
>>>>>>> 07jun2012 01:40:03
>>>>>>> 07jun2012 01:40:03
>>>>>>> 07jun2012 03:09:37
>>>>>>> 07jun2012 03:09:37
>>>>>>> 07jun2012 03:11:48
>>>>>>>
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