Re: st: Reshape with prefix using a varlist

[Richard Murphy <r1ch4rd.murphy@gmail.com>]

Thanks you guys,
I think that trick is very helpful.

Best Richard


On 15 March 2011 01:58, Nick Cox <njcoxstata@gmail.com> wrote:
> Rebecca is correct.
>
> Another way to do it, without a loop:
>
> unab myvars : country1-country244
> local myvars : subinstr local myvars " " " @", all
>
> That fixes every variable name except the first, which lacks a
> preceding "@", but you can just supply that directly to -reshape-:
>
> reshape ... @`vars', ...
>
> Nick
>
> On Tue, Mar 15, 2011 at 2:29 AM, Rebecca Pope <rebecca.a.pope@gmail.com> wrote:
>> Richard,
>> I know you've gotten what you need to accomplish the task at hand, but
>> I'd like to address your original question, in case you may find this
>> trick useful at a later date...
>>
>> If you want a series of the form @var1 @var2 etc, you can always make
>> Stata write the bulk of the command for you. I've used variants of
>> this for all sorts of purposes (e.g. sticking "i." or "c." in front of
>> a list of variables).
>>
>> /*use this if all countries are countryi*/
>> local vars ""
>> forvalues i=1/244 {
>> local vars "`vars' @country`i'"
>> }
>>
>> /*use this if you have names that vary from the countryi naming convention*/
>> unab varlist: country1 - country244
>> local vars ""
>> foreach var of local varlist {
>> local vars "`vars' @`var' "
>> }
>>
>> Then you could submit, using your example, -reshape wide `vars',
>> i(inst year) j(LEVEL) string-.
>> Hope this helps,
>> Rebecca
>>
>> On Mon, Mar 14, 2011 at 8:51 PM, Richard Murphy
>> <r1ch4rd.murphy@gmail.com> wrote:
>>>
>>> That's a very good point, I hadn't considered going in the other
>>> direction (even longer) and then collapsing when need be.
>>> Thanks for this, I think i will give this a try.
>>>
>>> Best
>>> Richard
>>>
>>>
>>> On 14 March 2011 18:35, Nick Cox <njcoxstata@gmail.com> wrote:
>>> > I think I would make this even -long-er if it were mine.
>>> >
>>> > reshape long country , i(year inst LEVEL)
>>> >
>>> > Then whatever reductions you want would be -egen- or -collapse- or -contract-.
>>> >
>>> > Why do I suggest this? You are already imagining that you need to
>>> > combine a loop over variables with totals over observations. Think how
>>> > much more of that you would need with yet more variables.
>>> >
>>> > Nick
>>> >
>>> > On Tue, Mar 15, 2011 at 1:21 AM, Richard Murphy
>>> > <r1ch4rd.murphy@gmail.com> wrote:
>>> >> The label "country1-country244" represents the remaining 244
>>> >> variables, containing the total amount of students from that country
>>> >> at that level in a uni-year.
>>> >> Are you suggesting something along the lines of
>>> >> foreach x in varlist eu uk {
>>> >>
>>> >>
>>> >> On 14 March 2011 18:02, Nick Cox <njcoxstata@gmail.com> wrote:
>>> >>> Thanks. That clarifies some things but not others. In your example,
>>> >>> you have 7 headings but 6 columns of data. What is
>>> >>> "country1-country244"? A variable label?
>>> >>>
>>> >>> The totals for groups are easily computable using -egen, total()- with
>>> >>> your present structure.
>>> >>>
>>> >>> On Tue, Mar 15, 2011 at 12:45 AM, Richard Murphy
>>> >>> <r1ch4rd.murphy@gmail.com> wrote:
>>> >>>> Hi Nick ,
>>> >>>> I appreciate that it looks foolish making a wide dataset even wider,
>>> >>>> but I don't think its that bad in this case.
>>> >>>> I have university by degree level by year data. For each of these i
>>> >>>> have the number of students coming from 244 different countries, along
>>> >>>> with total EU and total OS.
>>> >>>>
>>> >>>> year    instit  LEVEL   os      uk      eu country1-country244
>>> >>>> 1994    1       ug              12      146     0
>>> >>>> 1994    1       pgr             3       335     3
>>> >>>> 1994    1       pgt     1       101     0
>>> >>>> 1995    1       ug              7       119     0
>>> >>>> 1995    1       pgr             4       300     9
>>> >>>> 1995    1       pgt             6       59      17
>>> >>>>
>>> >>>> There are 3 levels of degree, which i would like to make wide. So that
>>> >>>> I would have a panel dataset for universities over time. The reason
>>> >>>> why i want to do this is that I want to calculate the cross
>>> >>>> subsidisation that occurs between the degree levels, and for this I
>>> >>>> need the totals for each within an observation.
>>> >>>>
>>> >>>> I need to do this for all the countries as i'm using a Card
>>> >>>> Shift-Share approach as an instrument for changes in overseas numbers,
>>> >>>> which i would like to define in various different ways throughout the
>>> >>>> analysis (EU, NonEU, Asia, ect).
>>> >>>>
>>> >>>> And i would like the prefix, so that the variable names fit into my
>>> >>>> pre existing do files for the analysis.
>>> >>>>
>>> >>>> Best regards
>>> >>>> Richard
>>> >>>>
>>> >>>>
>>> >>>> On 14 March 2011 17:24, Nick Cox <njcoxstata@gmail.com> wrote:
>>> >>>>> Please tell us directly more about your dataset and why you think
>>> >>>>> -reshape wide- is a good idea. From what you say it just make most
>>> >>>>> analyses more difficult. Also, how many variables will you end up
>>> >>>>> with?
>>> >>>>>
>>> >>>>> Nick
>>> >>>>>
>>> >>>>> On Tue, Mar 15, 2011 at 12:13 AM, Richard Murphy
>>> >>>>> <r1ch4rd.murphy@gmail.com> wrote:
>>> >>>>>> Hi all,
>>> >>>>>> I want to reshape long data to wide, putting the 'j' string variable
>>> >>>>>> at the begging of the stub.
>>> >>>>>> This would be fine if I have a limited number of variables as i can
>>> >>>>>> just use the @ function.
>>> >>>>>> reshape wide @var1 @var2 @var3 @var4, i(instit year) j(LEVEL) string
>>> >>>>>>
>>> >>>>>> But this does not work if i use the variable list functionality of
>>> >>>>>> reshape. I would like to know if their is an easier way of doing this,
>>> >>>>>> rather than typing in all 244 variables preceded by @.
>>> >>>>>> reshape wide @var1-@var244, i(instit year) j(LEVEL) string
>
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