[R-pkg-devel] Warning that are Unintentionally OS-Specific (Maybe Bug in warning?)

Hi Fran?ois,

I thought that was the issue, too, but I confirmed it wasn't that by 
adding a print statement right above the warning in my code. The print 
statement displays the message even when the warning (one line below 
with no conditionals between) doesn't show anything.

Also, why would it behave differently when options(warn=1) is set 
rather than the default of options(warn=0)?

Thanks,

Bill


On 7/20/2016 3:06 PM, Fran?ois Michonneau wrote:

Hi Bill,

   The problem is not with the warning() function but with your if()
test that triggers the warning. It probably has something to do with
slight differences in rounding. I suggest you use debug() or browser()
on each platform to see why your condition is TRUE or FALSE.

   Cheers,
   -- Fran?ois

On Wed, Jul 20, 2016 at 2:42 PM, Bill Denney <bill at denney.ws> wrote:

Hi,

I'm developing the PKNCA package, and I've got an odd difference 
between
warning behavior on different operating systems that I can't figure 
out.

When I run the following code on Windows 10 (with R 3.3.0), I get the
following warning:

library(PKNCA)
source("https://raw.githubusercontent.com/billdenney/pknca/master/tests/testthat/generate.data.R") 

tmpconc <- generate.conc(2, 1, 0:24)
tmpconc$conc <- 0
tmpdose <- generate.dose(tmpconc)
myconc <- PKNCAconc(tmpconc, conc~time|treatment+ID)
mydose <- PKNCAdose(tmpdose, dose~time|treatment+ID)
mydata <- PKNCAdata(myconc, mydose)
myresult <- pk.nca(mydata)

Warning messages:
1: In pk.calc.half.life(conc = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  :
   Too few points for half-life calculation (min.hl.points=3 with 
only 0
points)
2: In pk.calc.half.life(conc = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  :
   Too few points for half-life calculation (min.hl.points=3 with 
only 0
points)

When I run the code on Linux (Ubuntu 16.04 with R 3.3.1), I do not 
get a
warning.  When I run the code on Linux after "options(warn=1)", I 
get the
warning.  I have confirmed that the same code path is taken in both 
Windows
and Linux by simply inserting a print statement next to the 
warning.  The
actual warning code is:

     warning(sprintf(
       "Too few points for half-life calculation (min.hl.points=%g 
with only
%g points)",
       min.hl.points, nrow(dfK)))

This platform inconsistency is causing issues with my package 
because the
package expects the warnings, and the user should know about the 
warnings.
I've got test cases expecting the warnings, and they fail everywhere 
but
Windows 
(https://cran.r-project.org/web/checks/check_results_PKNCA.html).

Does anyone have an idea why warnings may behave differently on Windows
compared to non-Windows platforms?  Is this a bug in R somewhere?  
(I've not
been able to make a simpler example that triggers the issue, 
unfortunately.)

Thanks,

Bill