Hi Kenny, yes, there's only so much you can do with S3 methods penetrating other packages' code; Iñaki discusses this in the blog about the r-quantities project found at:
https://www.r-spatial.org/r/2018/08/31/quantities-final.html#fitting-linear-models-with-quantities I'm not sure whether making "var" a generic would not shift the problem to the next function not being generic, you could experiment with that. On 1/20/19 6:39 PM, Kenny Bell wrote: > Hi all, > > I am running into problems using `summary.lm` as calling `var` on a `units` > object does not retain the `units` attribute. > > The units package addresses this issue for `mean` by implementing > `mean.units`: > > units:::mean.units > function (x, ...) > { > .as.units(NextMethod(), units(x)) > } > > This is, however, not possible for `var` (as it's not a generic), which > breaks `summary.lm`: > > ``` > library(units) > #> udunits system database from C:/R/Library/3.5/units/share/udunits > iris$Sepal.Length <- set_units(iris$Sepal.Length, "cm") > > summary(lm(Sepal.Length ~ Sepal.Width, > data = iris)) > #> Error in Ops.units(mean(f)^2, var(f)): both operands of the expression > should be "units" objects > ``` > > Created on 2019-01-21 by the [reprex package](https://reprex.tidyverse.org) > (v0.2.1.9000) > > Apologies if `stats` package emails shouldn't go here. > > Cheers, > Kenny > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > -- Edzer Pebesma Institute for Geoinformatics Heisenbergstrasse 2, 48151 Muenster, Germany Phone: +49 251 8333081 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
