Sum rows of DataFrame

Specific Domains Data
,
1

What is the most idiomatic way to sum up all rows of a DataFrame into a row of totals? Can you give an example where the DataFrame contains numeric and non-numeric columns?

2

How about
https://dataframes.juliadata.org/stable/lib/functions/#DataAPI.describe
?

3

Easiest way (when there are non-numeric columns) is

julia> df = DataFrame(a = [1, 2, 3], b = [5, 6, 7], c = ["x", "y", "z"]);

julia> df.rowsum = sum.(eachrow(df[:, names(df, Real)]))
3-element Vector{Int64}:
  6
  8
 10

In the mini-language there is

julia> df = DataFrame(a = [1, 2, 3], b = [5, 6, 7], c = ["x", "y", "z"]);

julia> transform(df, AsTable(names(df, Real)) => ByRow(sum) => :rowsum)
3×4 DataFrame
 Row │ a      b      c       rowsum 
     │ Int64  Int64  String  Int64  
─────┼──────────────────────────────
   1 │     1      5  x            6
   2 │     2      6  y            8
   3 │     3      7  z           10

But be warned, the “mini-language” version will make some NamedTuples under the hood, and if you have 1000+ columns this may impact performance.

With DataFramesMeta there is

julia> @rtransform df :rowtotal = sum(AsTable(names(df, Real)))
3×4 DataFrame
 Row │ a      b      c       rowtotal 
     │ Int64  Int64  String  Int64    
─────┼────────────────────────────────
   1 │     1      5  x              6
   2 │     2      6  y              8
   3 │     3      7  z             10
4

I think I should provide an example of expected result. I am looking for the sum of rows to produce a final row with the totals, like we do in a spreadsheet:

julia> df = DataFrame(a=[1,2,3], b=[1,1,1], c=["a","b","c"])

# run magic function
julia> magic(df)

| a | b |
---------
| 6 | 3 |
5

Oh sorry! I thought you meant the opposite


julia> combine(df, names(df, Real) .=> sum)
1×2 DataFrame
 Row │ a_sum  b_sum 
     │ Int64  Int64 
─────┼──────────────
   1 │     6      3
3 Likes
6

For ByRow(sum) it will not create a NamedTuple and it should scale.

8

Ah correct! I forgot about that optimization.