Can change shape of range with ARRAYFORMULA() in Google Sheets? - google-sheets

Question

My intention is to convert a single line of data into rows consist of a specific number of columns in Google Sheets.
For example, starting with the raw data:
A
B
C
D
E
F
1
id1
attr1-1
attr2-1
id2
attr2-1
attr2-2
And the expected result is:
(by dividing columns by three)
A
B
C
1
id1
attr1-1
attr1-2
2
id2
attr2-1
attr2-2
I already know that it's possible a bit manually, like:
=ARRAYFORMULA({A1:C1;D1:F1})
But I have to start over with it every time the target range is moved OR the subset size needs to be changed (in the case above it was three)!
So I guess there will be a much more graceful way (i.e. formula does not require manual update) to do the same thing and suspect ARRAYFORMULA() is the key.
Any help will be appreciated!

Answer 1

I added a new sheet ("Erik Help") where I reduced your manually entered parameters from two to one (leaving only # of columns to be entered in A2).
The formula that reshapes the grid:
=ArrayFormula(IFERROR(VLOOKUP(SEQUENCE(ROUNDUP(COUNTA(7:7)/A2),A2),{SEQUENCE(COUNTA(7:7),1),FLATTEN(FILTER(7:7,7:7<>""))},2,FALSE)))
SEQUENCE is used to shape the grid according to whatever is entered in A2. Rows would be the count of items in Row 7 divided by the number in A2 (rounded to the nearest whole number); and the columns would just be whatever number is entered in A2.
Example: If there are 11 items in Row 7 and you want 4 columns, ROUNDUP(11/4)=3 rows to the SEQUENCE and your requested 4 columns.
Then, each of those numbers in the grid is VLOOKUP'ed in a virtual array consisting of a vertical SEQUENCE of ordered numbers matching the number of data pieces in Row 7 (in Column 1) and a FLATTENed (vertical) version of the Row-7 data pieces themselves (in Column 2). Matches are filled into the original SEQUENCE grid, while non-matches are left blank by IFERROR

Answer 2

Though it's a bit messy, managed to get it done thanks to SEQUENCE() function anyway.
It constructs a grid by accepting number of rows/columns input, and that was exactly I was looking for.
For reference set up a sheet with the sample data here:
https://docs.google.com/spreadsheets/d/1p972tYlsPvC6nM39qLNjYRZZWGZYsUnGaA7kXyfJ8F4/edit#gid=0

Answer 3

Use a custom formula
Although you already solved this. If you are doing this kind of thing a lot, it could be beneficial to look into Apps Script and custom formulas.
In this case you could use something like:
function transposeSingleRow(range, size) {
// initialize new range
let newRange = []
// initialize counter to keep track
let count = 0;
// start while loop to go through row (range[0])
while (count < range[0].length){
// add a slice of the original range to the new range
newRange.push(
range[0].slice(count, count + size)
);
// increment counter
count += size;
}
return newRange;
}
Which works like this:
The nice thing about the formula here is that you select the range, and then you put in a number to represent its throw, or how many elements make up a complete row. So if instead of 3 attributes you had 4, instead of calling:
=transposeSingleRow(A7:L7, 3)
you could do:
=transposeSingleRow(A7:L7, 4)
Additionally, if you want this conversion to be permanent and not dependent on formula recalculation. Making it in run fully in Apps Script without using formulas would be neccesary.
Reference
Apps Script
Custom Functions