I strictly need to use the summarise_at to compute a weighted mean, with weights based on the values of another column

    df %>% summarise_at(.vars = vars(FACTOR,tv:`smart tv/console`), 
                  .funs = weighted.mean, w=INVESTMENT, na.rm=TRUE)

It always shows the error: 'INVESTMENT' is not found.

I then tried with:

df %>%summarise_at(.vars = vars(FACTOR,tv:`smart tv/console`), 
               .funs = weighted.mean, w=vars(INVESTMENT), na.rm=TRUE)

But in this case : Evaluation error: 'x' and 'w' must have the same length.

Why is this? Am I doing anything wrong? Do you have hints to solve this issue? Thanks


You can specify the weights directly within the weighted.mean() function, within the call to funs() like so:

data.frame(x=rnorm(100), y=rnorm(100), weight=runif(100)) %>%
      summarise_at(vars(x,y), funs(weighted.mean(., w=weight)))
  • $\begingroup$ summarise_at has now been superseded by across. Your example code may now look something like this: data.frame(x=rnorm(100), y=rnorm(100), weight=runif(100)) %>% summarise(across(x:y, ~weighted.mean(., w = weight))) $\endgroup$
    – JPD
    Sep 23 '20 at 8:15

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