How calculate the sum of several functions in vba

[BRUCEWAYNE]

HI5 folks, I'd like to know how to calculate the sum of one function that has several values from 1,2,3 .... to n

the function is

z = (((1 + w) ^ 2))l = (((p) ^ (n - 1)))

y = ((z * l)) ^ ( / 2)

I'd like to know how to calculate the sum ∑ of y, for example from 1,2,3 .... to 10

when w=0,5 p= 0,993449, n= 10 doing the harder way line per line should return

199,0484.

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How do it by writting in vba code the sum ∑ of y in order to get the results in a faster way ?

Please can someone help me with this problem ? many thanks

 

[lrobbo314]

What is the value of the 'L' variable?

 

[BRUCEWAYNE]

the function is

z = (((1 + w) ^ 2))



l = (((p) ^ (n - 1)))



y = ((z * l)) ^ ( / 2)


the 'L' variable is l = (((p) ^ (n - 1)))

I'd like to know how to calculate the sum ∑ of y, for example from 1,2,3 .... to 10

when w=0,5 p= 0,993449, n= 10 doing the harder way line per line should return

199,0484.

<tbody>
</tbody>

How do it by writting in vba code the sum ∑ of y in order to get the results in a faster way ?

many thanks in advance

 

[Marcelo Branco]

Maybe I did not understand exactly what you need - I found a different result for n = 10, that is: 138,791

Function GetSum(w As Double, p As Double, k As Long)
    Dim Z As Double, y As Double, l As Double, n As Long
    Dim dbSum As Double
    
    Z = (((1 + w) ^ 2))
    For n = 1 To k
        l = (((p) ^ (n - 1)))
        y = ((Z * l)) ^ ((n) / 2)
        'Just to check...
        Debug.Print "y(" & n & ") = " & y
        dbSum = dbSum + y
    Next n
    GetSum = dbSum
End Function

Debug.Print produced these results

y(1)	=	1,5
y(2)	=	2,23526
y(3)	=	3,309105
y(4)	=	4,866744
y(5)	=	7,110695
y(6)	=	10,32122
y(7)	=	14,88319
y(8)	=	21,32093
y(9)	=	30,34325
y(10)	=	42,90062

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Formula (; as argument separator in my Excel version)
=getsum(0,5;0,993449;10)

M.

 

[Marcelo Branco]

I think you meant n = 1, 2,....11
Result = 199,0484

M.

 

[BRUCEWAYNE]

ok. yeah it's a mistake that i made here , when put 11 i gave Result = 199,0484.

I´ve got a doubt : How Can i see these written results (one by one), (such as in the column B) produced by Debug.Print from n = 1, 2,....11? How do you that?

I would appreciate to hear from you

 

[Marcelo Branco]

Alt+F11 to open VBEditor

Menu
View > Immediate window

or Ctrl+G

Debug.Print in my function displays y(1), y(2)....y in the Immediate Window

M.

 

[Marcelo Branco]

If you do want to see the results in a worksheet execute the sub Main that calls the sub sGetSum

Sub Main()
    Dim w As Double, p As Double, k As Long
    
    w = 0.5
    p = 0.993449
    k = 10
    sGetSum w, p, k
End Sub

Sub sGetSum(w As Double, p As Double, k As Long)
    Dim Z As Double, y As Double, l As Double, n As Long
    Dim dbSum As Double, dbResults() As Double
    
    ReDim dbResults(1 To k, 1 To 2)
    
    Z = (((1 + w) ^ 2))
    
    For n = 1 To k
        l = (((p) ^ (n - 1)))
        y = ((Z * l)) ^ ((n) / 2)
        dbResults(n, 1) = n
        dbResults(n, 2) = y
        dbSum = dbSum + y
    Next n
    
    'Display results
    Columns("B:C").ClearContents
    Range("B1:C1") = Array("y", "Value")
    Range("B2").Resize(k, 2) = dbResults
    Range("B2").Offset(k) = "Result"
    Range("C2").Offset(k) = dbSum
End Sub

M.

 

[BRUCEWAYNE]

Debug.Print produced these results that you mentioned above:

y(1)	=	1,5
y(2)	=	2,23526
y(3)	=	3,309105
y(4)	=	4,866744
y(5)	=	7,110695
y(6)	=	10,32122
y(7)	=	14,88319
y(8)	=	21,32093
y(9)	=	30,34325
y(10)	=	42,90062

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PRODUCT =

1636964555

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How can i find in vba the product Π of y(x)= y(1)* y(2)* y(3)* y(4)* y(5)* y(6)* y(7)* y(8)* y(9)* y(10)???****** id="cke_pastebin" style="position: absolute; top: 343px; width: 1px; height: 1px; overflow: hidden; left: -1000px;">

1636964555

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</body>

 

[Marcelo Branco]

Try

Function GetProd(w As Double, p As Double, k As Long)
    Dim Z As Double, y As Double, l As Double, n As Long
    Dim dbProd As Double
    
    Z = (((1 + w) ^ 2))
    dbProd = 1
    For n = 1 To k
        l = (((p) ^ (n - 1)))
        y = ((Z * l)) ^ ((n) / 2)
        'Just to check...
        Debug.Print "y(" & n & ") = " & y
        dbProd = dbProd * y
    Next n
    GetProd = dbProd
End Function

Excel

Formula (; as argument separator in my excel version)
=GetProd(0,5;0,993449;10)

M.