interflex

1. Fixed the kernel estimator's adaptive bandwidth: the normalizer is now the geometric mean of the moderator's density at the observations (Abramson's rule) instead of over the whole density grid, fixing "subscript out of bounds" and "$ operator is invalid" errors on moderators with gaps or long tails.

2. With a fixed bw, kernel windows are now wider than in 1.4.0 (typically 1.5-3x on well-behaved moderators); results under the default cross-validated bw change little.

3. Kernel local fits that are unidentified, fail, or have no usable kernel weights are now dropped with a warning, or the call stops with a clear "Inappropriate bandwidth" error, instead of being filled with zeros or crashing; cross-validation can no longer silently return bw = -Inf; an invalid bw is now rejected with an error.

4. interflex() no longer sets the global option interflex.uniform_ci_warned.

5. inter.test() now documents its return value.

6. interflex() gains bw.select, bw.se.mult and bw.ess.min, which expose the bandwidth selection rules of the kernel estimator ("cv.min", the default; "cv.1se"; "cv.1se.ess"; "ess") and pass them, together with bw, through to the kernel smoothing step of the lasso estimator with a continuous treatment. Use bw.select = "cv.1se" when cross-validation cannot separate the candidate bandwidths.

7. citation("interflex") now lists the methods paper (Hainmueller, Mummolo and Xu 2019), the practical guide to the modern estimators (Liu, Liu and Xu, arXiv:2504.01355, forthcoming as a Cambridge Element), and the package.