On Thu, Oct 04, 2012 at 10:55:03PM +0200, Nelle Varoquaux wrote:
> This problem does not occur with the r version of the lars lasso.

I don't know R. Could you send me R code to reproduce the behavior under
R.

I've been looking at the problem more precisely, and in our
implementation, the gram matrix of the active set becomes very very
ill-conditioned (1e-15 eigenval). Choleski of the gram matrix blows up. I
wonder how they avoid that problem in R.

The naive implementation of Alejandro avoids it by using linalg.solve,
but that really defeats the purpose of lars, which is really to
iteratively compute only updates.

Gaƫl

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