when to use map() function and when to use summarise_at()/mutate_at()
问题 Can anyone give a suggestion regarding when to use the map() (all map_..() functions) and when to use summarise_at() / mutate_at() ? E.g. if we are doing some modification to the column of vectors then we do not need to think map() ? If we have a df / have a column has a list in it then we need to use map() ? Does map() function always need to be used with nest() function? Anyone could suggest some learning videos regarding this. And also how to put lists in df and modeling multiple lists at