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Re: st: duplicated datetime variable differs from original datetime variable it was derived from
From
Nick Cox <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: duplicated datetime variable differs from original datetime variable it was derived from
Date
Tue, 12 Nov 2013 12:26:06 +0000
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
[email protected]
On 12 November 2013 12:01, Milena Przheska
<[email protected]> 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 <[email protected]> wrote:
>> Same answer. Use a -double-.
>>
>> Nick
>> [email protected]
>>
>>
>> On 12 November 2013 11:51, Milena Przheska
>> <[email protected]> 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 <[email protected]> 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
>>>> [email protected]
>>>>
>>>>
>>>> On 12 November 2013 11:33, Phil Clayton <[email protected]> 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 <[email protected]> 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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