weighted.mean.units throwing Ops.units error when weights are units objects

[bocinsky]

library(units)
#> udunits system database from /Library/Frameworks/R.framework/Versions/3.6/Resources/library/units/share/udunits

# breaks
weighted.mean(x = units::set_units(1:10, "kg"),
              w = units::set_units(1:10, "m^2"))
#> Error in Ops.units(w, 0): both operands of the expression should be "units" objects

# breaks
weighted.mean(x = 1:10,
              w = units::set_units(1:10, "m^2"))
#> Error in Ops.units(w, 0): both operands of the expression should be "units" objects

# works
weighted.mean(x = units::set_units(1:10, "kg"),
              w = 1:10)
#> 7 [kg]

# works
weighted.mean(x = 1:10, 
              w = 1:10)
#> [1] 7

^{Created on 2019-05-10 by the reprex package (v0.2.1)}

Session info

devtools::session_info()
#> ─ Session info ──────────────────────────────────────────────────────────
#>  setting  value                       
#>  version  R version 3.6.0 (2019-04-26)
#>  os       macOS Mojave 10.14.4        
#>  system   x86_64, darwin15.6.0        
#>  ui       X11                         
#>  language (EN)                        
#>  collate  en_US.UTF-8                 
#>  ctype    en_US.UTF-8                 
#>  tz       America/Denver              
#>  date     2019-05-10                  
#> 
#> ─ Packages ──────────────────────────────────────────────────────────────
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#> 
#> [1] /Library/Frameworks/R.framework/Versions/3.6/Resources/library

[edzer]

Thanks! This might do it; your second case cannot be solved here AFAICT, as it calls base::weighted.mean.default, which we cannot intercept in units.

[bocinsky]

Thanks Edzer! Dropping the units from w does the trick, but I'm not sure I understand what you did there with units(x * uw[1]). Shouldn't the units of x remain the same in the output?

[edzer]

Ah, of course - I forgot you divide by the sum of the weights.