[R] gam error message: matrix not +ve definite

[R. Michael Weylandt]

On Sun, Oct 7, 2012 at 3:00 PM, garth <dboyce at dal.ca> wrote:
> Hello,
>
> I'm running a multimodel analysis which involves fitting several GAM models
> as implemented in package mgcv.  The issue I'm having is that when I try to
> fit my model, gam gives me the following error message: 'Error in
> initial.sp(w * X, S, off) : S[[2]] matrix is not +ve definite.' The strange
> part of this is that the error message stops my model fitting function when
> run on a linux platform, but not on my local windows machine. Ordinarily I
> would just run the analysis on my local machine, but I need to run this from
> the linux machine to take advantage of the much larger computing capacity.
> The version of mgcv(1.7-21) and R (2.15.1) is the same on both machines.
>
> The data set to which the model if fitted is too large to post here but it
> contains 2209 observations, and the model is of the form: gam(Response~Year
> + s(Dayofyear,k=5,bs='cc') + s(Longitude,Latitude,k=4) +
> s(Coast_distance,k=4), family=Gamma('log'), data=dat, gamma=1.4)
>
> I realize this is a very particular question, but any help would be really
> appreciated.
> Thanks,
> Dan.
>

It's a bit of a shot in the dark, but might it reflect data that is
"close" to not being non-positive-definite and differences in BLAS?

The only other think I'd try would be a

update.packages(checkBuilt = TRUE, ask = FALSE)

to just update every package you've got installed. It might not be
that the error is from mgcv proper, but rather a dependency thereof
which is in different versions between the machines.

Also, I note you're posting through Nabble. Nabble actually only
mirrors the R-Help mailing list, so we (the majority of respondents
who don't use Nabble) don't get a forum view, but rather only emails
of individual posts. The net result of this is that we don't see
context of your follow-up postings unless you specifically include it,
but it's much appreciated if you do. I believe there might also be a
button which does so automatically, but I'll leave finding that to
you.


Cheers,
Michael