gbm: Generalized Boosted Regression Models

gbm 2.1.6

Corrected the number of arguments for gbm_shrink_gradient() in gbm-init.c (#50). (Thanks to CRAN for highlighting the issue.)
Removed unnecessary dependency on gridExtra.
Switched to using lapply() instead of parallel::parLapply() whenever n.cores = 1.
Calling gbm() with distribution = "bernoulli" will now throw an error whenever the response is non-numeric (e.g., 0/1 factors will throw an error instead of possibly crashing the session.) (#6). (Thanks to @mzoll.)
Calling gbm() with distribution = "multinomial" now comes with a warning message; multinomial support has always been problematic and since this package is only being maintained for backwards compatibility, it likely will not be fixes unless someone makes a PR.
Switched from RUnit to tinytest framework. The test.gbm(), test.relative.influence(), and validate.gbm() functions will remain for backwards compatability. This is just the start, as more tests will be added in the future (#51).

Fixed a long standing bug that could occur when using k-fold cross-validation with a response that's been transformed in the model formula (#30).
Fixed a but that would crash the session when giving "bad" input for n.trees in the call to predict.gbm() (#45). (Thanks to @ngreifer.)
Fixed a bug where calling predict() could throw an error in some cases when n.trees was not specified.

Fixed bug that occurred whenever distribution was a list (e.g., "pairwise" regression) (#27).
Fixed a bug that occurred when making predictions on new data with different factor levels (#28).
Fixed a bug that caused relative.influence() to give different values whenever n.trees was/wasn't given for multinomial distributions (#31).
The plot.it argument of gbm.perf() is no longer ignored (#34).
Fixed an error that occurred in gbm.perf() whenever oobag.curve = FALSE and overlay = FALSE.

Switched from CHANGES to NEWS file.
Updated links and maintainer field in DESCRIPTION file.
Fixed bug caused by factors with unused levels (#5).
Fixed bug with axis labels in the plot() method for "gbm" objects (#17).
The plot() method for "gbm" objects is now more consistent and always returns a "trellis" object (#19). Consequently, setting graphical parameters via par will no longer have an effect on the output from plot.gbm.
The plot() method for "gbm" objects gained five new arguments: level.plot, contour, number, overlap, and col.regions; see ?plot.gbm for details.
The default color palette for false color level plots in plot.gbm() has changed to the Matplotlib 'viridis' color map.
Fixed a number of references and URLs.