Find all increments of +1's starting from a given number in a column in excel - excel

Question

I have 2 columns x and y
x Y
0 1
1.645 7.897
3.444 6.4387
2.345 5.9090
3.890 5.4322
4.789 3.4321
5.666 4.1111
keeping x at a constant value ( say i pick 3.890) i want to find all increments of +1's of the corresponding Y column . In the above example I want (5.4322 + 1 + 1 + 1 ) upto a certain range.In the above example i want the values (6.4387, 7.987) .If an exact +1 value does not exist i want the closest value to it .Is there a formula i can use to achieve this in excel ? . Any help is much appreciated.
expected output :
New column
5.4322
6.4387
7.897

Answer 1

Suppose you have the following named ranges:
x being values under x column;
y being values under y column;
Pick_x being the selected value from x column.
Enter the following formula in Cell G2 and drag it down to G8:
=IF(INDEX(y,MATCH(Pick_x,x,0))+1*(ROW(A1)-1)>MAX(y),"",INDEX(y,MATCH(Pick_x,x,0))+1*(ROW(A1)-1))
It will return the corresponding y value +1s based on the selected x value, but will show blank if the +1 value is outside the range set by y column.
Then enter the following array formula (confirm by pressing Ctrl+Shift+Enter in the formula bar) in Cell H2 and drag it down to H8:
{=IFERROR(INDEX(y,MATCH(MIN(ABS(y-G2)),ABS(y-G2),0)),"")}
It will return the corresponding closes match from y column based on the value in Column G, and return blank if there is no value in Column G.
I used Column G as a helper column but you can choose to replace G2 in the second formula with the first formula, but it will make the formula too long to be easily understood.
If I change the x value to 4.789, Column H will return the following:
Let me know if I've misinterpreted your question. Cheers :)