Error in aggregate.data.frame : arguments must have same length

Question

I keep getting this error and I'm not quite sure what it means. All of my variable names are consistent and there are no typos. Am I missing something here?

The code

datNewagg <- aggregate (dataNew, by = list('x', 'y', 'z', 'a', 'ab'), 
                                                             FUN = mean)  

Produces the error

  Error in aggregate.data.frame(datNew, by = list("x", "y",  : 
  arguments must have same length

Answer 1

I used get this error.
The simple solution to remove this error is to write all the variables along with their dataset name like "ds_name$var_name".
I'm not sure what is the dataset name is your case, so I'll give you another similar example.

curYearRev <-aggregate(hr$Year.Total, by = list(hr$Hospital_ID,hr$District_ID,hr$Instrument_ID) , FUN = sum)

Here, "hr" is the dataset name and "Year.Total", "Hospital_ID", "District_ID", "Instrument_ID" are the variables in "hr" dataset.

Writing aggregate functions in this way will never give you any errors again.

Answer 2

Assuming it's not a typo (the data frame is called dataNew in your call but datNew in the error), are x, y, z, a and ab the names of columns in dataNew?

Some functions, like subset, will allow you to specify column names of the object they're working on directly. The aggregate function doesn't, so any columns of dataNew listed in the by argument need to specifically referred to as such. Try this:

datNewagg <- aggregate(dataNew,
    by = list(
        x = dataNew$x,
        y = dataNew$y,
        z = dataNew$z,
        a = dataNew$a,
        ab = dataNew$ab),
    FUN = mean)