# specific groupby

Dear community users,

I am trying to find a way to group by my columns with a specific formula but I coudn't do it. Basically, I would like to go from a table like this:

 3 x1 3 a 4 x2 3 b 5 x3 3 c 6 x4 3 d 7 x5 4 e 8 x6 4 f 9 x7 4 g 10 x8 4 h 11 x... 4 i 12 4 j 13 4 k 14 5 l 15 5 m 16 5 n

to a table like this:

 3 x1 mean(x1/a;x1/b;x1/c;x1/d) 4 x2 mean(x2/e;x2/f;x2/g;x2/h;x2/i;x2/j;x2/k) 5 x3 mean(x3/l;x3/m;x1/n) 6 x4 .......

Thank you for your help,

CO,

You can use:
- math formula node for each row = x1/a and so on
- group by node: groups: 3;4;5 and aggregation: mean (math formula result)

Is this the solution you were looking for?

Robert

Robert,

The problem is that the 2nd column has less rows than the 4th column. - math formula node for each row = x1/a and so on would give me col2/col4 and I will not have x1/b, x1/c ,x1/d,...

I hope  I was clear enough.

Thank you for your help,

Chakib,

Robert,

The problem is that the 2nd column has less rows than the 4th column. - math formula node for each row = x1/a and so on would give me col2/col4 and I will not have x1/b, x1/c ,x1/d,...

I hope  I was clear enough.

Thank you for your help,

Chakib,

I attached the solution (numerical input).
Please verify if the result  is correct.

 3 x1 mean(x1/a;x1/b;x1/c;x1/d) 4 x2 mean(x2/e;x2/f;x2/g;x2/h;x2/i;x2/j;x2/k)

Robert

Thank you Robert, it works wery well,

Best regards,

CO,