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Coefficient of determination for non-linear equations system (nlsystemfit)

2 messages · Antti Simola, Arne Henningsen

#
Hello everyone,

I have estimated system of three linear equations with one non-linear 
restrictions with nlsystemfit. I was wondering how I can calculate the 
R-squared (or some alternative coefficient of determination) for the 
whole system. This is automatically given by linear systemfit but not by 
nlsystemfit. I can get the values for each of the equations separately, 
but apparently not for the whole system.

I'm also wondering why separate equations' objects all appear in 
together with a command like:

nl.system <- nlsystemfit()

nl.system$eq[i]

but e.g. the following produces NULL as the value for the individual 
objects, e.g. R-squared

eq.1 <- nl.system$eq[1]

eq.1$r2

Cheers,

Antti
4 days later
#
Dear Antti
On 20 November 2012 10:24, Antti Simola <asimola78 at gmail.com> wrote:
Please read the FAQ at http://www.systemfit.org/
You have to do this manually, e.g. by equation (43) in the paper:
   http://www.jstatsoft.org/v23/i04/paper
As the "eq" component is a "list" (see documentation), you must use
double brackets:
   nl.system$eq[[i]]
You can directly use:
   nl.system$eq[[i]]$r2

Best wishes from Copenhagen,
Arne

--
Arne Henningsen
http://www.arne-henningsen.name