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Re: st: Problem with datetime functions


From   Nick Cox <njcoxstata@gmail.com>
To   "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>
Subject   Re: st: Problem with datetime functions
Date   Tue, 11 Jun 2013 15:35:02 +0100

It's not a bug in Stata. It's yours.

On your -generate- you need a data type other than -float- to hold
every digit exactly. -long- should work, but whenever dates and times
are mentioned, thinking -double- is safe.

-tostring, force- shows that you knowingly run risks of damaging the data.

But why -generate- a new variable? Use the display format  %tdCYND

clonevar myday2 = myday
format myday2 %tdCYND

is a better way to proceed if you really need a new variable.

Nick
njcoxstata@gmail.com


On 11 June 2013 15:18, George Vega Yon <g.vegayon@gmail.com> wrote:
> Dear list members,
>
> I'm facing a problem while generating an integer from day-time
> variable. In short, what I (in stata %td format) have is
>
> myday
> 01jan2002
> 02jan2002
> 03jan2002
> 04jan2002
> ...
>
> What I want is
>
> myday2
> 20020101
> 20020102
> 20020103
> 20020104
> ...
>
> Which is I though I could generate by:
>
> gen myday2 = year(myday)*10000 + month(myday)*100 + day(myday)
>
> But acctually returns
>
> myday2
> 20020100
> 20020102
> 20020104
> 20020104
>
> So, it seems that stata is rounding my new variable. I don't want to
> say that this is a bug, but what are the alternatives?.
>
> I've solve this with:
>
> format %tdCCYYNNDD myday
> tostring myday, u gen(myday2) force
> destring myday2, replace
>
> myday2
> 20020101
> 20020102
> 20020103
> 20020104
>
> But still, stata rounding my integers doesn't sound very good. Any ideas?
>
> Thanks!
>
> George Vega
>
> PS: Running on windows 7
> c(stata_version) = 12.1
> c(version) = 12.1
> c(born_date) = "18 Dec 2012"
> c(flavor) = "IC"
> c(os) = "Windows"
> c(osdtl) = "64-bit"
> c(machine_type) = "PC (64-bit x86-64)"
> c(byteorder) = "lohi"
>
>
>
> George Vega Yon
> 7 647 2552
> http://cl.linkedin.com/in/georgevegayon
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