Hi.

I'm using GWR method in my research through the spgwr package (by the way,
thanks to the programmers), and I've already obtained some results; but I
would like to know why sometimes when I run the LMZ.F3GWR.test command, it
shows me the following error message:

"Error in  solve.default(t(x) %*% diag(wj) %*% x)
system is computationally singular: reciprocal condition number =
1.81708e-18"

As far as I know, this might be related to the B matrix used in the paper
by Leung et al (2000), but I don't understand what's happening since I
obtained the results of the test for certain regressions. I'm using a
sample of 803 cases and thirteen variables (including the dependent one).
In the "wrong" regression I use the default gaussian function for the
weights (fixed kernel) and the AIC for the bandwidth, while I'd got fine
results for combinations of bi-square function and CV score, and for
gaussian function and CV score. Does it has to do with choosing the AIC
(actually, I've tried a bi-square function with AIC, but I couldn't even
obtain the bandwidth from it)? Does it depends on the value of the
bandwidth (maybe too small)? or may it be solved in anyway?

Thank you beforehand for any comment.

Best regards,

Diana.

-- 
*Diana Gutiérrez Posada (Doctoranda)*
REGIO*lab*, Laboratorio de Análisis Económico Regional
Dpto. de Economía Aplicada, Universidad de Oviedo
Avda. del Cristo S/N, 33006 - Oviedo (Asturias)
Correo electrónico: d.gutierrez.posada@gmail.com
Web REGIO*lab*: http://www.uniovi.net/regiolab

	[[alternative HTML version deleted]]

