Computing the ChiSquare - vba

Question

I am writing a user-defined function in excel vba. So this new function:
takes 4 input value
some calculation to generate into 8 numbers. ( 2 arrays - each array has 4 numbers)
do a chisquare test
return 1 output value
Code:
Sub test()
Dim A, B, C, D As Variant
A = 33
B = 710
C = 54
D = 656
'Observed Value
Dim O_A As Variant
Dim O_B As Variant
Dim O_V As Variant
Dim O_D As Variant
'Define Observer Value
O_C_A = 'Some Calucation'
O_C_B = 'Some Calucation'
O_T_C = 'Some Calucation'
O_T_C = 'Some Calucation'
'Expected Value
Dim E_C_A As Variant
Dim E_C_B As Variant
Dim E_T_C As Variant
Dim E_T_D As Variant
'Define Expected Value
E_C_A = 'Some Calucation'
E_C_B = 'Some Calucation'
E_T_C = 'Some Calucation'
E_T_D = 'Some Calucation'
'Create array(2x2)
Dim Chi_square_result As Variant
Dim my_array(1, 1)
my_array(0, 0) = O_C_Mesaurement
my_array(0, 1) = O_C_Balance
my_array(1, 0) = O_T_Measurement
my_array(1, 1) = O_T_Balance
Dim my_array2(1, 1)
my_array2(0, 0) = E_C_Mesaurement
my_array2(0, 1) = E_C_Balance
my_array2(1, 0) = E_T_Measurement
my_array2(1, 1) = E_T_Balance
'Create a chi square test formula'
Dim formula(1 To 5) As String
formula(1) = "CHITEST("
formula(2) = my_array
formula(3) = ","
formula(4) = my_array2
formula(5) = ")"
'Chi Square
Chi_square_result = evaluate(Join(formula, ""))
end sub
It gives a runtime error '13', saving type mismatch. This is because of the concatenation of the formula.

Answer 1

If you are writing a function, you have your format wrong.
Function Chi_square_result(A as Long, B as Long, C as Long, D as Long) as Double
'All your manipulations here
Chi_square_result = (Your math equation)
End Function
You also never defined my_array1, I am assuming it is supposed to be where you typed 'my_array'. I also do not think Join is your best bet. You are trying to do an awful lot of array manipulation, and I think your dimensions are getting you. It would be better to do it in a more straight forward way.

Answer 2

The evaluate is expecting worksheet cell ranges. Use the Excel Application object or WorksheetFunction object to compute the function within VBA.
This proofs out.
Dim dbl As Double
Dim my_array1(1, 1)
my_array1(0, 0) = 1
my_array1(0, 1) = 2
my_array1(1, 0) = 3
my_array1(1, 1) = 4
Dim my_array2(1, 1)
my_array2(0, 0) = 2
my_array2(0, 1) = 3
my_array2(1, 0) = 4
my_array2(1, 1) = 5
dbl = Application.ChiTest(my_array1, my_array2)
Debug.Print dbl
Result from the VBE's Immediate window: 0.257280177154182.