by CODE, sort: egen m = min(real(newdate1))
would seem to be an alternative. But if you
wanted to use a numeric version of -newdate1-
later, using -destring- would be better.
In addition, note that there is an FAQ on
this issue:
How can I generate a variable containing the last of
several dates?
http://www.stata.com/support/faqs/data/lastdate.html
which despite its title does cover minimum as
well as maximum.
Nick
[email protected]
Sergiy Radyakin
> Sorry, Gaby, I was not particularly careful with the syntax, just
> wanted to communicate the idea. To be more precise, the resulting
> variable is a string, so "min" does not work with it. So, first we
> need to:
>
> destring newdate1, generate(nd1)
>
> Now nd1 is a numeric variable. And second, don't write the parenthesis
> () after by:
>
> by CODE: egen m=min(nd1)
>
>
> . l
>
> +----------------+
> | CODE newdate |
> |----------------|
> 1. | 10 0410 |
> 2. | 10 0414 |
> 3. | 10 0408 |
> 4. | 10 0301 |
> 5. | 20 0208 |
> |----------------|
> 6. | 20 0216 |
> 7. | 20 0208 |
> 8. | 20 0210 |
> +----------------+
>
> +----------------------------+
> | CODE newdate nd1 beg |
> |----------------------------|
> 1. | 10 0301 301 301 |
> 2. | 10 0408 408 301 |
> 3. | 10 0410 410 301 |
> 4. | 10 0414 414 301 |
> 5. | 20 0208 208 208 |
> |----------------------------|
> 6. | 20 0208 208 208 |
> 7. | 20 0210 210 208 |
> 8. | 20 0216 216 208 |
> +----------------------------+
Ana Gabriela Guerrero Serdan
> > Thanks, I managed to swap the month first and then the
> > day. But when trying to calculate the minimum it says
> >
> > by(CODE): egen beg=min(newdate1)
> > invalid syntax
> > r(198);
> >
> > I been trying to calculate the mimimum of newdate
> > without the sort and its also not possible... !?
> > Should I firs set the var as date?
Sergiy Radyakin
> > > this will swap the day and month in the [string]
> > > variable Date1:
> > > gen newdate1=substr(Date1,3,2)+substr(Date1,1,2)
> > > As long as Date2 is always later than Date1, you
> > > care only about Date1
> > > for the minimum:
> > > sort CODE newdate1
> > > by(CODE): egen beg=min(newdate1)
> > >
> > > Quite similarly you proceed to the end dates.
Ana Gabriela Guerrero
> > > I have a very basic question but I havent find the
> > > > date commands when I only have day and month.
> > > >
> > > > I have information on interviews carried out and
> > > want
> > > > to know the range of interview per province
> > > (CODE), so
> > > > I want to calculate the min and max of the dates
> > > > within each province.
> > > >
> > > >
> > > > . list CODE Date1 Date2 Date3
> > > >
> > > > +-------------------------------+
> > > > | CODE Date1 Date2 Date3 |
> > > > |-------------------------------|
> > > > 1. | 01 2704 |
> > > > 2. | 01 2704 3004 |
> > > > 3. | 01 2704 1505 |
> > > > 4. | 01 2505 |
> > > > 5. | 01 2605 |
> > > > |-------------------------------|
> > > > 6. | 02 2705 0106 |
> > > > 7. | 02 2805 0606 |
> > > >
> > > > etc..
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
