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AW: st: AW: forvalues & replace not working under two 'not equal to' conditions


From   "Martin Weiss" <[email protected]>
To   <[email protected]>
Subject   AW: st: AW: forvalues & replace not working under two 'not equal to' conditions
Date   Tue, 10 Nov 2009 17:47:31 +0100

<> 


For clarification, you could provide the solution, i.e. the dummies that you
actually want to see as your final output, for your chosen example. Makes it
considerably easier to work towards code for you...



HTH
Martin


-----Ursprüngliche Nachricht-----
Von: [email protected]
[mailto:[email protected]] Im Auftrag von joe j
Gesendet: Dienstag, 10. November 2009 17:39
An: [email protected]
Betreff: Re: st: AW: forvalues & replace not working under two 'not equal
to' conditions

Thanks Martin. I think I wasn't clear enough in the last mail. I was
not looking at various combinations of firm_id, nation_id and
contract_id 'for each observation'. Rather I was looking at the
similarity or difference of firm_id/nation_id 'between two or more
observations' under each contract_id.

Based on Martin's suggestion I could derive group_d (see below). But I
still can't get right nongroup_f, which equals 1 (for all
observations) if firm_id and nation_id are different for two or more
observations under each contract_id (but it takes a value 1, wrongly,
for all observations in the data)

*deriving group_d (this works)
egen groups=group(firm_id nation_id)

bys contract_id (groups):  /*
*/ gen byte distinctcount_group_d= /*
*/ (groups[_n]==groups[_n+1])

bys contract_id (groups):  /*
*/ replace distinctcount_group_d=1 /*
*/ if (groups[_n]==groups[_n-1])

*2 deriving nongroup_f doesnt work (e.g. it should be 0 for contract_id=1)
bys contract_id (groups):  /*
*/ gen byte distinctcount_nongroup_f= /*
*/ (groups[_n]~=groups[_n+1]) & (nation_id[_n]~=nation_id[_n+1])

bys contract_id (groups):  /*
*/ replace distinctcount_nongroup_f=1 /*
*/ if (groups[_n]~=groups[_n-1]) & (nation_id[_n]~=nation_id[_n-1])

On Tue, Nov 10, 2009 at 4:14 PM, Martin Weiss <[email protected]> wrote:
>
> <>
>
> I think a variable denoting the combinations between the three ids is a
good
> place to start for you:
>
>
>
> *************
> clear*
> inp byte(contract_id firm_id) nation_id:mylabel, auto
> 1   2   "US"
> 1   2   "US"
> 4   3   "UK"
> 4   3   "US"
> 8   4   "US"
> 8   4   "UK"
> 8   3   "US"
> 9   5   "US"
> 9   4   "UK"
> 9   3   "US"
> 10   5   "US"
> 10   5   "US"
> 10   6   "NL"
> 10   7   "NL"
> 10   4   "UK"
> 10   4   "CH"
> end
>
> egen groups=group(contract_id firm_id nation_id)
>
> l, sepby(con) noobs
> *************
>
>
>
> HTH
> Martin
>
>
> -----Ursprüngliche Nachricht-----
> Von: [email protected]
> [mailto:[email protected]] Im Auftrag von joe j
> Gesendet: Dienstag, 10. November 2009 16:04
> An: [email protected]
> Betreff: st: forvalues & replace not working under two 'not equal to'
> conditions
>
> My dataset has three variables 1. contract_id, 2. firm_id and 3.
> nation_id. I want to create 4 variables, each of which gets a value of
> 1 if certain conditions are met. The variables I want to create are
> specific to the contract id, and are:
>
> 1. group_d = 1 when both firm_id and nation_id are same for two or
> more firms with the same contract id
> 2. group_f = 1  when firm_id is same but nation_id is different for
> two or more firms with the same contract id
> 3. nongroup_d = 1  when firm_id is different but nation_id is same for
> two or more firms with the same contract id
> 4 .nongroup_f = 1  when both firm_id and nation_id are different for
> two or more firms with the same contract id
>
> The following code works well for the first three variables, but not
> for the last, nongroup_f; the value is 1 for all observations. I can't
> figure out why.
>
> This is a sample code:
>
> clear
> inp str10(contract_id firm_id   nation_id)
> 1   2   "US"
> 1   2   "US"
> 4   3   "UK"
> 4   3   "US"
> 8   4   "US"
> 8   4   "UK"
> 8   3   "US"
> 9   5   "US"
> 9   4   "UK"
> 9   3   "US"
> 10   5   "US"
> 10   5   "US"
> 10   6   "NL"
> 10   7   "NL"
> 10   4   "UK"
> 10   4   "CH"
> end
>
>
> *1.group_d . WORKS!
> gen group_d=.
> forvalues i=1/`=_N'{
> bys contract_id: replace group_d=1 if firm_id==firm_id[_n-`i'] &
> nation_id==nation_id[_n-`i']
> }
> forvalues i=1/`=_N'{
> bys contract_id: replace group_d=1 if firm_id==firm_id[_n+`i'] &
> nation_id==nation_id[_n+`i']
> }
>
> *2.group_f  WORKS!
> gen group_f=.
> forvalues i=1/`=_N'{
> bys contract_id: replace group_f=1 if firm_id==firm_id[_n-`i'] &
> nation_id!=nation_id[_n-`i']
> }
> forvalues i=1/`=_N'{
> bys contract_id: replace group_f=1 if firm_id==firm_id[_n+`i'] &
> nation_id!=nation_id[_n+`i']
> }
>
> *3. nongroup_d  WORKS!
> gen nongroup_d=.
> forvalues i=1/`=_N'{
> bys contract_id: replace nongroup_d=1 if firm_id!=firm_id[_n-`i'] &
> nation_id==nation_id[_n-`i']
> }
> forvalues i=1/`=_N'{
> bys contract_id: replace nongroup_d=1 if firm_id!=firm_id[_n+`i'] &
> nation_id==nation_id[_n+`i']
> }
>
> *4.nongroup_f DOESN'T WORK!!
> gen nongroup_f=.
> forvalues i=1/`=_N'{
> bys contract_id: replace nongroup_f=1 if (firm_id~=firm_id[_n-`i']) &
> (nation_id~=nation_id[_n-`i'])
> }
> forvalues i=1/`=_N'{
> bys contract_id: replace nongroup_f=1 if (firm_id~=firm_id[_n+`i']) &
> (nation_id~=nation_id[_n+`i'])
> }
> *
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