Re: [Gretl-devel] a very strange case of arima (poor)convergence

I'm attaching a variant of the hansl code posted recently by Oleh, which may be a little easier to understand than the original. Summary: Oleh's hansl code standardizes a "difficult" exogenous regressor in the arma context. His results are for the most part a bit better than standard libgretl arma (though still not quite as good as x13as). The dataset used in Oleh's examples, bad_data.gdt, can be found attached to his posting at http://lists.wfu.edu/pipermail/gretl-devel/2018-October/009185.html (see http://lists.wfu.edu/pipermail/gretl-devel/attachments/20181026/da605227/... ) For convenience, this dataset can now also be found at http://ricardo.ecn.wfu.edu/pub/gretl/bad_data.gdt Allin