Aggregate multiple columns at once

Question

I have a data-frame likeso   x  lt - id1 id2    val1  val2 val3 val4 1   a   x    1    9 2   a   x    2    4 3   a   y    3    5 4   a   y    4    9 5   b   x    1    7 6   b   y    4    4 7   b   x    3    9 8   b   y    2    8   I wish to aggregate the above by id1  amp  id2  I want to be able to get the means for val1  val2  val3  val4 at the same time   How do i do this   This is what i currently have but it works just for 1 column   agg  lt - aggregate x val1  list id11   x id1  id2  x id2   mean  names agg  3   lt - c  val1      Rename the column   Also  how do i rename the columns which are outputted as means in the same statement given above

User · Answer

You could try   agg  lt - aggregate list x val1  x val2  x val3  x val4   by   list x id1  x id2   mean

User · Answer

We can use the formula method of aggregate   The variables on the  rhs  of   are the grouping variables while the   represents all other variables in the  df1   from the example  we assume that we need the mean for all the columns except the grouping   specify the dataset and the function  mean    aggregate   id1 id2  df1  mean      Or we can use summarise each from dplyr after grouping  group by   library dplyr  df1   gt       group by id1  id2    gt        summarise each funs mean     Or using summarise with across  dplyr devel version -    0 8 99 9000      df1   gt        group by id1  id2    gt       summarise across starts with  val    mean       Or another option is data table   We convert the  data frame  to  data table   setDT df1   grouped by  id1  and  id2   we loop through the subset of data table   SD  and get the mean   library data table  setDT df1    lapply  SD  mean   by     id1  id2      data  df1  lt - structure list id1   c  a    a    a    a    b    b     b    b     id2   c  x    x    y    y    x    y    x    y     val1   c 1L   2L  3L  4L  1L  4L  3L  2L   val2   c 9L  4L  5L  9L  7L  4L   9L  8L     Names   c  id1    id2    val1    val2     class    data frame   row names   c  1     2    3    4    5    6    7    8

[r] Aggregate multiple columns at once

Examples related to r

Examples related to aggregate