you have an * at the start of your definition of B11, therefore bothgcc*$B11
evaluates to bothgcc* and you get the message you saw.
Michael Blasnik
[email protected]
----- Original Message -----
From: "Dale W. Larson" <[email protected]>
To: <[email protected]>
Sent: Friday, September 26, 2003 4:28 PM
Subject: st: Syntax Problem in Nonlinear Regression
> Hi,
>
> I am having trouble defining the estimating equation for a nonlinear
regression
> in the fcn program. I am using Version 7.
>
> In a string of variables and coefficients of the form (varname*$B#), the
> program stops at one with the error message:
>
> "varname* invalid name"
>
> In other words, it thinks the * is a part of the varname, rather than an
> operator.
>
> I tried putting the varname in parentheses, to distinguish it from the
> operator, but then I get the error message, "Unknown function ()".
>
> Here is the exact expression from my do-file:
> ((kuwait90*$B8)+(kuwait91*$B9)+(kuwait92*$B10)+(bothgcc*$B11))
>
> The regression ran okay until I added the (bothgcc*$B11). Can anyone see
what
> I am doing wrong?
>
> FYI, the command, summarize bothgcc, works fine, i.e., for this command it
> recognizes "bothgcc" as a variable.
>
> Below is my entire do-file.
>
> Dale
> --------------------------------------------------------------------------
--
> -----
> use Dataset4, clear
> program define nlnonlinear
> version 7.0
> if "`1'"=="?" {
> #delimit ;
> global S_1 "B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11";
> #delimit cr
> *
> global B1=.8
> global B2=.8
> global B3=-.2
> global B4=-.2
> *
> global B5=-1
> global B6=-1
> *
> global B7=-1
> *
> global B8=-1
> global B9=-1
> global B10=-1
> *
> *global B11=1
> exit
> *X1 is real GDP of importing country
> *X2 is real GDP of exporting country
> *X3 is the population of the importing country
> *X4 is the population of the exporting country
> *
> *X5 is the tariff of the importing country
> *X6 is the MFN tariff of the exporting country
> *
> *X7 is distance between capital cities
> *
> *X8 is a dummy variable=1 when trade involved Kuwait in 1990
> *X9 is a dummy variable=1 when involved Kuwait in 1991
> *X10 is a dummy variable=1 when trade involved Kuwait in 1992
> *
> *X11 is a dummy variable=1 when both countries are members of GCC
> }
> #delimit ;
> replace `1'= (crealgdpm^$B1)*(crealgdpx^$B2)*(popm^$B3)*(popx^$B4)
> *(tm^-1)*(tx^$B6)
> *(odistance^$B7)
> *e^((kuwait90*$B8)+(kuwait91*$B9)+(kuwait92*$B10)+(bothgcc*$B11));
> #delimit cr
> end
> *End of program. Ready to do nonlinear regression.
> set more off
> nl nonlinear averagem1
>
*
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* http://www.stata.com/support/faqs/res/findit.html
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