median

df.median() // median of values per every comparable column
df.median { age and weight } // median of all values in `age` and `weight`
df.medianFor { age and weight } // median of values per `age` and `weight` separately
df.medianOf { (weight ?: 0) / age } // median of expression evaluated for every row

df.median()
df.age.median()
df.groupBy { city }.median()
df.pivot { city }.median()
df.pivot { city }.groupBy { name.lastName }.median()