[Gretl-devel] New (or fairly new) in CVS

I thought I might draw people's attention to a few new things in CVS, and encourage testing: "bundles": we have a new data type, the bundle. This was Jack's idea, and we worked on it earlier this summer. It's mostly intended to make life easier for writers of ambitious function packages. It's documented in the new chapter of the User's Guide titled "Gretl data types". (That may not the permanent home for the bundle documentation but it'll do for now.) filters: I've been corresponding with Stephen (D.S.G.) Pollock and under the Filters menu for time-series data we now have two items that he has advocated (and coded in the IDEOLOG software that he described at last year's gretl conference). That is, the Butterworth filter and polynomial trend fitting. The Butterworth filter is described, with an example, in the chapter of the User's Guide titled "Special functions in genr". Polynomial trend fitting is, of course, something you could do in gretl before, but Stephen's algorithm is fast and light on memory, and does not require you to add powers of t to the dataset. It's also numerically robust, being based on "orthogonal polynomials" rather than linear regression on powers of time. Both of these things are also scriptable, via new functions bwfilt and polyfit (the first is documented, the second not yet). A smaller thing is that in the model table you can now select the precision of the printing in terms of digits after the decimal point rather than total significant digits if you wish. A larger thing is in the works and likely to be unveiled before long, but it's not quite ready yet. Watch this space! Allin