Google Sheet Sparkline for every nth column

Question

I would like to add a Sparkline to a sheet showing the evolution of a value.

My table looks like this

value #1	diff former value	value #2	diff former value	value #3	diff former value
Sparkline here		Sparkline here		Sparkline here
10	0	8	-2	9	1

My naive guess for the "Sparkline here" cell was (e.g. for C2)

    =SPARKLINE($A3:c3)

and for instance for E2

    =SPARKLINE($A3:e2)

unfortunately this takes the 0 (B3) and -2 (D2) into account.

Question: How can I create a sparkline that would only take every second value into account, i.e. 10, 8, 9. Best if this could be done without adding a helper row/column somewhere else.

Answer 1

Try

=sparkline(filter(A3:F3, isodd(column(A3:F3)))) 

or, depending on your locale

=sparkline(filter(A3:F3; isodd(column(A3:F3))))

This will include only the 'odd' columns in the specified range.