[R] OSX-specific Bug in randomForest

[Duncan Murdoch]

I've cc'd this to the package maintainer, Andy Liaw 
<andy_liaw using merck.com>. I'm not sure he reads this list.

Duncan Murdoch

On 2024-10-23 1:26 a.m., Stevie Pederson wrote:
> Hi,
> 
> It appears there is an OSX-specific bug in the function
> `randomForest.default()` Going by the source code at
> https://github.com/cran/randomForest/blob/master/R/randomForest.default.R
> the bug is on line 103
> 
> If the vector `cutoff` is formed using `cutoff <- rep(1/9, 9)` (line #101)
> the test on line 103 will fail on OSX as the sum is greater than 1 due to
> machine precision errors.
> 
> sum(rep(1 / 9, 9)) - 1
> # [1] 2.220446e-16
> 
> This will actually occur for a scenario when the number of factor levels
> (nclass) is 9, 11, 18, 20 etc.The problem does not occur on Linux, and I
> haven't tested on WIndows.
> 
> A suggestion may be to change the opening test
> 
> if (sum(cutoff) > 1 || ...)
> 
> to
> 
> if (sum(cutoff) - 1  > .Machine$double.eps || ...
> 
> however, I'm sure there's a more elegant way to do this
> 
> Thanks in advance
> 
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> 
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