Is there a weighted.median() function?

Question

I'm looking for something similar in form to weighted.mean(). I've found some solutions via search that write out the entire function but would appreciate something a bit more user friendly.

Answer 1

The following packages all have a function to calculate a weighted median: 'aroma.light', 'isotone', 'limma', 'cwhmisc', 'ergm', 'laeken', 'matrixStats, 'PSCBS', and 'bigvis' (on github).

To find them I used the invaluable findFn() in the 'sos' package which is an extension for R's inbuilt help.

findFn('weighted median') 

Or,

???'weighted median'

as ??? is a shortcut in the same way ?some.function is for help(some.function)

Answer 2

Some experience using the answers from @wkmor1 and @Jaitropmange.

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I've checked 3 functions from 3 packages, isotone, laeken, and matrixStats. Only matrixStats works properly. Other two (just as the median(rep(x, times=w) solution) give integer output. As long as I calculated median age of populations, decimal places matter.

Reproducible example. Calculation of the median age of a population

df <- data.frame(age = 0:100,                  pop = spline(c(4,7,9,8,7,6,4,3,2,1),n = 101)$y)  library(isotone) library(laeken) library(matrixStats)  isotone::weighted.median(df$age,df$pop) # [1] 36 laeken::weightedMedian(df$age,df$pop) # [1] 36 matrixStats::weightedMedian(df$age,df$pop) # [1] 36.164 median(rep(df$age, times=df$pop)) # [1] 35 

Summary

matrixStats::weightedMedian() is the reliable solution