Re: st: how to program an equivalent of "egen mean" for an equation

[Nick Cox <njcoxstata@gmail.com>]

That need not be any problem. If the variable already exists, just
-drop- it first.
Nick
njcoxstata@gmail.com


On 1 May 2013 14:06, Francesca Colantuoni <f.colantuoni9@gmail.com> wrote:
> Oh OK. So, that's not the way to go.
> Thanks a lot Nick,
> Francesca
>
> On Tue, Apr 30, 2013 at 7:28 PM, Nick Cox <njcoxstata@gmail.com> wrote:
>> -egen- does not allow a -replace- option.
>> Nick
>> njcoxstata@gmail.com
>>
>>
>> On 30 April 2013 22:59, Francesca Colantuoni <f.colantuoni9@gmail.com> wrote:
>>> Thank you so much Nick! By placing a space between -egen- and `y' it
>>> does not give me that error. It gives me other errors
>>>  (specifically: "option replace not allowed nlh_n6 refused query,
>>> rc=198"), but I'll keep on working.
>>> Francesca
>>>
>>>
>>> On Tue, Apr 30, 2013 at 9:41 AM, Nick Cox <njcoxstata@gmail.com> wrote:
>>>> The specific error here is that you need a space between -egen- and
>>>> `y'. Stata is thinking that you are referring to a program or command
>>>>
>>>> egen__00000F
>>>>
>>>> and naturally it doesn't exist.   (Temporary variable names created by
>>>> Stata are all 8 characters long and begin with a double underscore.)
>>>>
>>>> I haven't look at the rest of your code.
>>>>
>>>> Nick
>>>> njcoxstata@gmail.com
>>>>
>>>>
>>>> On 30 April 2013 14:15, Francesca Colantuoni <f.colantuoni9@gmail.com> wrote:
>>>>> I am trying to program a non linear least square function using panel
>>>>> data. I have to create a sort of "within estimator" by having the
>>>>> estimation routine compute the average of the function for each value
>>>>> of the parameters, and such average needs to be plugged back in the
>>>>> original function in the following fashion: x_st-(mean)x_st=f(beta,
>>>>> gamma) - value_f((mean)beta,(mean)gamma)
>>>>> where s=market, t=time.
>>>>> While x_st-(mean)x_st is observed and I can compute it, I don't know
>>>>> how to implement the mean of the function in the routine, because I
>>>>> need to compute it for each estimated value of the parameters, but
>>>>> also for each individual (market) of the dataset, over time. I have
>>>>> tried this way, but obviously it does not work:
>>>>>
>>>>> program nlfrncs
>>>>> version 12.1
>>>>>
>>>>> if "`1'" == "?" {
>>>>> global S_1 "w b_ns b_s g2_ns g2_s g3_ns g3_s"
>>>>> global w=0
>>>>> global b_ns=-1
>>>>> global b_s=-2
>>>>> global g2_ns=0.5
>>>>> global g2_s=0.5
>>>>> global g3_ns=0.5
>>>>> global g3_s=0.5
>>>>>
>>>>> tempvar Y
>>>>> quietly {
>>>>> by market, sort:
>>>>> egen`Y'=mean(ln($w*exp($b_ns*price1+$g2_ns*price2+$g3_ns*price3)+(1-$w)*(y*exp($b_s*price1+$g2_s*price2+$g3_s*price3)+i*exp($b_s*price1+$g2_s*f_price2+$g3_s*f_price3))))
>>>>> , replace
>>>>> }
>>>>> exit
>>>>>
>>>>> }
>>>>> replace `1'=ln($w*exp($b_ns*price1+$g2_ns*price2+$g3_ns*price3)+(1-$w)*(y*exp($b_s*price1+$g2_s*price2+$g3_s*price3)+i*exp($b_s*price1+$g2_s*f_price2+$g3_s*f_price3)))-`Y'
>>>>> end
>>>>>
>>>>> I get the error: unrecognized command: egen__00000F
>>>>> Any suggestion or direction will be greatly appreciated.
>>>>> Francesca
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