Subtracting every other cell in VBA

[G_Chas]

Hello,
Im new in programming and specifically in VBA. I have a problem where i have 1 huge column (E) and i need to subtract each cell with the sum of other previous ones, in every other cell. In particular, i need every north (N) pile to be the number written, minus the sum of all previous north piles, and for south piles the exact same thing. Does anyone have a clue about that?

 

[Ezguy4u]

I believe you are showing us the input. Could you show us an example of what you want for the output?

 

[G_Chas]

Hello @Ezguy4u, that is the input, correct. For example the 315N pile (986) needs to be =315N(986)-314N(272)-313N(226)-312N(222) and for the south pile the exact same thing(south piles only). That subtraction needs to occur every time there a north pile (or south) and subtract every north pile (or south) up to this point.

 

[Peter_SSs]

Welcome to the MrExcel board!

Is this what you mean?

Sub NS()
  Dim a As Variant
  Dim i As Long, NTot As Long, STot As Long, tmp As Long
  
  a = Range("D5", Range("D" & Rows.Count).End(xlUp)).Value
  NTot = a(1, 1)
  STot = a(2, 1)
  For i = 3 To UBound(a) Step 2
    tmp = a(i, 1)
    a(i, 1) = a(i, 1) - NTot
    NTot = NTot + tmp
    tmp = a(i + 1, 1)
    a(i + 1, 1) = a(i + 1, 1) - STot
    STot = STot + tmp
  Next i
  Range("E5").Resize(UBound(a)).Value = a
End Sub

My sample data in columns A:D, code results in column E (for checking - they could be written back to column D if you want)

G_Chas.xlsm
	A	B	C	D	E
1
2
3
4
5	N			222	222
6	S			229	229
7	N			226	4
8	S			222	-7
9	N			272	-176
10	S			725	274
11	N			986	266
12	S			998	-178
13	N			1257	-449
14	S			1262	-912
15	N			1538	-1425
16	S			1549	-1887
Sheet1

If this is not what you want, please provide the expected results (preferably with XL2BB) and explain again

 

[G_Chas]

Hello @Peter_SSs, thank you!! This exactly what i want but the programm needs to subtract the already subtracted value from the previous cell. For example:
E12 = D12(998) - [D10(725) - D8(222) - D6(229)] - D8(222) - D6(229).
By hand this results in 273 but in the program it gives back -178.
I hope I made it more clear and not the other way around.
Thank you for your time.

 

[Peter_SSs]

E12 = D12(998) - [D10(725) - D8(222) - D6(229)] - D8(222) - D6(229).

One example is not enough to go on (for me at least)

If this is not what you want, please provide the expected results (I mean all of them) (preferably with XL2BB) and explain again