RE: st: could someone pls explain me this

[tashi lama <ltashi32@hotmail.com>]

is summarize in the code to specify the variable we are looking to find r(min) ? Looks like it...

 

Thanx..
----------------------------------------
> From: ltashi32@hotmail.com
> To: statalist@hsphsun2.harvard.edu
> Subject: RE: st: could someone pls explain me this
> Date: Mon, 30 Apr 2012 18:24:34 +0000
>
> thank you. I still have some clouds.
>
> 1.Why do we have to summarize the temp var?
>
> 2.Minimum such obs no r(min). Are we looking the minimum obs in the tempvar? Is it 3 in the following example?
>
>
>
> epcom noncom __000001 |
> |------------------------------------------|
> 1. | 18001 Acheres . |
> 2. | 18002 Ainay-Le_Vieil . |
> 3. | 18003 Les Aix -d'Angillion 3 |
> 4. | 18004 Allogny . |
> 5. | 18005 Allouis . |
>
>
>
>
> 3. Could we have said instead of minimum or maximum no, non-missing obs no because there is only one obs in tempvar?
>
> ----------------------------------------
> > Date: Mon, 30 Apr 2012 18:37:56 +0100
> > Subject: Re: st: could someone pls explain me this
> > From: njcoxstata@gmail.com
> > To: statalist@hsphsun2.harvard.edu
> >
> > The code
> >
> > tempvar tv1
> > gene `tv1'=_n if depcom==18003
> > summ `tv1', meanonly
> > local index=r(min)
> > local mymacro=nomcom[`index']
> > drop `tv1'
> >
> > is a way of looking up the value of -nomcom- when -depcom- is 18003.
> > The temporary variable contains observation numbers for which -depcom-
> > is 18003. A certain way of finding such an observation if any exist is
> > to find the minimum such observation number. The maximum would do fine
> > as an alternative. The code could be shortened
> >
> > tempvar tv1
> > gene `tv1'=_n if depcom==18003
> > summ `tv1', meanonly
> > local mymacro=nomcom[r(min)]
> > drop `tv1'
> >
> > The main point of similar code is to automate value look-up. It's
> > usually a long-winded way to proceed if you are working interactively.
> >
> > Nick
> >
> > On Mon, Apr 30, 2012 at 6:24 PM, tashi lama <ltashi32@hotmail.com> wrote:
> >
> > > I am doing sth similar to what I found in archive titiled "Re: st: save the value of a string variable into a macro". I am not sure if I followed the code although it looks relatively st. forward.
> > >
> > >
> > >
> > > Here is the dataset and goal
> > >
> > > +-----------------------------+
> > > | depcom nomcom |
> > > |-----------------------------|
> > > 1. | 18001 Acheres |
> > > 2. | 18002 Ainay-le-Vieil |
> > > 3. | 18003 Les Aix-d'Angillon |
> > > 4. | 18004 Allogny |
> > > 5. | 18005 Allouis |
> > > +-----------------------------+
> > >
> > > Where depcom is an id. I want to save a specific values of the variable "nomcom" into a variable, for example, I want to obtain :
> > > . di "`mymacro'"
> > > Archeres
> > >
> > >
> > >
> > > The code is
> > >
> > >
> > >
> > > tempvar tv1
> > > gene `tv1'=_n if depcom==18003
> > > summ `tv1', meanonly
> > > local index=r(min)
> > > local mymacro=nomcom[`index']
> > > drop `tv1'
> > >
> > >
> > >
> > >
> > > I follow line 1 and 2. I am not sure why we need line 3. Line 4 established a macro which is used in line 5. But, I don't follow why the macro takes r(min) as expression. I would think the macro `index' should capture the value(the only value in fact) in tv1.
> >
> > *
> > * For searches and help try:
> > * http://www.stata.com/help.cgi?search
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/ 		 	   		  
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/