struggling summing my array - arrays

I am trying to fix a subroutine that creates an array of 10 Integers such that each element of the array stores the sum of its own index number and all previous indexes. (Indexes start at 1.) The values in the array would be:
1, 3, 6, 10, 15, 21, 28, 36, 45, 55
For example, the value 6 in the 3rd element is the sum of the index values 1 + 2 + 3. At the end all I am doing is copying the contents of the array to the range A1:J1.
The code I have thus far goes as follows:
Sub SumNum()
Dim Ints(1 to 10) As Integer
Dim Sum As Integer
Dim i As Integer
i = 0
For i = LBound(Ints) to UBound(Ints)
Sum = i + Ints(i)
Range("A1").offset(0,1).Value = Sum
Next i
End Sub
It seems in theory I guess that it should work out since I have the loop going and having the sum pasted to each offset, however this sub is giving me errors and unable to perform. Any guidance will be appreciated!
Edit: when I run my code the only output is on B2 of the value 10. Strange!

Range("A1:J1").Formula = "=(COLUMN()*(COLUMN()+1))/2"
Two things to note here:
You can assign a range to an array directly without looping. That is, after computing your array, you can say myRange.Value = myArray. You need to transpose the array if the range is a column.
The above code exploits a known mathematical formula: 1+2+3+...+n = (n(n+1))/2. It didn't need to compute any array. The formula applies this equation and gets the index from the Column property of each cell.
Hope this helps.

Related

Aggregating part of a 2d array in a column in said array

I have a 2d array, with flexible dimensions:
arr_emissions(1 to n, 0 to m)
Where n is 22 or larger, and m is 6 or larger.
In the smallest case column m = 6 should contain the sum of columns m = 2 - 5.
I could ofcourse simply add them, but as the dimensions of the array are flexible I would like to implement a more robust method, that preferly doesn't loop over the entire array.
I was hoping to implement the native application.WorksheetFormula.Sum(). I saw an implementation in this answer, but that only works for complete rows or columns.
Example:
I have arr_emissions(0 to 111,1 to 6). It is populated in a loop from 1 to 111.
The data in the array is as follows:
(1,1) #3-4-2020# 'a date value
(1,2) 1,379777
(1,3) 0
(1,4) Empty
(1,5) Empty
Don't know if this helps, but this takes a source array v and then populates a new array w with the sum of columns 2-4 of the corresponding row of v.
Sub x()
Dim v, i As Long, w()
'just to populate source array
v = Range("A1").CurrentRegion.Value
ReDim w(1 To UBound(v, 1))
For i = 1 To UBound(w)
'each element of w is sum of columns 2-4 of corresponding row of v
w(i) = Application.Sum(Application.Index(v, i, Array(2, 3, 4)))
Next i
'write w to sheet
Range("G1").Resize(UBound(w)) = Application.Transpose(w)
End Sub
Thanks to the answer from SJR I found myself a working solution. This is all within a larger piece of code, but for this example I filled some variables with fixed numbers to match my example from my question.
Dim days as Integer
days = 111
Dim emissions_rows as Integer
emissions_cols = 6
ReDim arr_emissions(0 To days, 1 To emissions_cols) As Variant
Dim arr_sum As Variant
Dim sum_str As String
sum_str = "Transpose(row(2:" & emissions_rows - 1 & "))"
arr_sum = Application.Evaluate(sum_str) '= Array(2,3,4,5)
arr_emissions(emissions_index, emissions_cols) = Application.Sum(Application.Index(arr_emissions, emissions_index + 1, arr_sum))
The code writes a string to include the variables, so to take the second column untill the second to last column, which is then evaluated into an array.
That array is then used within the sum function, to only sum over those columns.
The result is then written to the last column of arr_emissions().
emissions_index is an index that is used to loop over the array.

How to Pass an Array to and from a Function?

(Fair Warning, I am self taught on VBA so I apologize in advance for any cringe-worthy coding or notations.)
I have an estimating worksheet in excel. The worksheet will have a section for the user to input variables (which will be an array). The first input variable will "reset" the remaining input variables to a standard value when the first variable is changed. The standard values for the input variables are stored in a function in a module. I am attempting to fill the input variable array with the standard values from the function and then display those values on the sheet. I was easily able to do this without arrays but have had no luck in moving everything into arrays.
This is for excel 2010. I previously did not use arrays and created a new variable when needed, however the estimating sheet has grown much larger and it would be better to use arrays at this point. I have googled this question quite a bit, played around with removing and adding parenthesis, changing the type to Variant, trying to set the input variable array to be a variable that is an array (if that makes sense?), and briefly looked into ParamArray but that does not seem applicable here.
Dim BearingDim(1 To 9, 1 To 4, 1 To 8) As Range
Dim arrBearingGeneral(1 To 5, 1 To 8) As Range
Dim Test As Variant
Private Sub Worksheet_Change(ByVal Target As Range)
'Set General Variable array to cells on the worksheet
For i = 1 To 5
For j = 1 To 8
Set arrBearingGeneral(i, j) = Cells(9 + i, 3 + j)
Next j
Next i
'Set Bearing Input Variables to Cells on the Worksheet
For p = 1 To 4
For i = 1 To 9
Select Case p
Case Is = 1
Set BearingDim(i, p, 1) = Cells(16 + i, 4)
Case Is = 2
Set BearingDim(i, p, 1) = Cells(27 + i, 4)
Case Is = 3
Set BearingDim(i, p, 1) = Cells(37 + i, 4)
Case Is = 4
Set BearingDim(i, p, 1) = Cells(49 + i, 4)
End Select
Next i
Next p
'Autopopulate standard input variables based on Bearing Type
inputMD_StdRocker BearingType:=arrBearingGeneral(1, 1), _
arrBearingDim:=BearingDim
End Sub
Sub inputMD_StdRocker(ByVal BearingType As String, ByRef _
arrBearingDim() As Variant)
Dim arrBearingDim(1 To 9, 1 To 4)
Select Case BearingType
Case Is = "MF50-I"
For j = 1 To 2
arrBearingDim(2, j) = 20
arrBearingDim(3, j) = 9
arrBearingDim(4, j) = 1.75
Next j
arrBearingDim(5, 1) = 15
'There are numerous more select case, but those were removed to keep it
'short
End Select
End Sub
The expected output is my "BearingDim" Array will have certain array index values set to a standard value from the "inputMD_StdRocker" function. Then those values will be displayed in the cell that corresponds to the array index.
Currently, I get a compile error "Type Mismatch, Array or User-Defined Type Expected". I have been able to get around the type mismatch by removing the () from "arrBearingDim()" in the function title for "inputMD_StdRocker" however, it will not pass the values back to my "BearingDim" array.
Any help would be greatly appreciated.
This is a partial answer to what (I think) is a misunderstanding you have of how to use arrays. There are a few problems in your code.
First, you're defining a two-dimensional and a three-dimensional array of Ranges when I believe you really only want to store the values captured from the worksheet. (If I'm wrong, then you are never initializing the array of Ranges, so none of the ranges in the array actually point to anything.)
Secondly, it looks as if your initial array arrBearingGeneral is always filled from the same (static) area of the worksheet. If this is so (and you really do want the values from the cells, not an array of Range objects), then you can create a memory-based array (read this website, especially section 19). So the first part of your code can be reduced to
'--- create and populate a memory-based array
Dim bearingDataArea As Range
Dim arrBearingGeneral(1 To 5, 1 To 8) As Variant
Set bearingDataArea = ThisWorkbook.Sheets("Sheet1").Range("D10:K14")
arrBearingGeneral = bearingDataArea.Value
Optionally of course you can calculate the range of your data instead of hard-coding it ("D10:K14"), but this example follows your own example.
While this isn't a complete answer, hopefully it clears up an issue to get you farther down the road.

Array Addition, why start at 'i = 2'?

Using the Ruby language, have the function ArrayAdditionI(arr) take the array of numbers stored in arr and return the string true if any combination of numbers in the array can be added up to equal the largest number in the array, otherwise return the string false. For example: if arr contains [4, 6, 23, 10, 1, 3] the output should return true because 4 + 6 + 10 + 3 = 23. The array will not be empty, will not contain all the same elements, and may contain negative numbers.
Could someone please explain to me why this code starts at 'i=2' and not 'i=0'?
def ArrayAdditionI(arr)
i = 2
while i < arr.length
return true if arr.combination(i).map{|comb| comb.inject(:+)}.include?(arr.max)
i += 1
end
false
end
ArrayAdditionI(STDIN.gets)
Correct me if I'm wrong but with i=2, the while loop will iterate [2..4] and then stop. But does this allow for all the potential combinations?...=> code works, so obviously it does but I'm just not seeing it.
i is not the index of the array it the number of elements that is being used to create a combination. So if the max number in the array can be made with the sum of just two elements it stops if not it tries three and so on.
array.combination(i) returns all possible combination of elements in an array with length i.
For example
if
ar=[4, 6, 23, 10]
then
array.combination(2).to_a
returns
[[4,6],[4,23],[4,10],[6,23],[6,10],[23,10]]
So basically you need to find sum in your program and getting sum requires combinations of length two (You need to operands in all possible combination ). Hence you don't start with i=0 or i=1.
You can not give it an empty array,so 0 leads to false. If you have 1 element in an array,it is also meaningless. So I guess 2 is a starting point which makes this test meaningful.

Find sign change in array

I have data in excel which starts with negative values, passes zero and reaches a certain positive value. I put this particular set of data in an array dataset1 = {-9.5,-7,-5.25,-3,-1.1,0,1,5,20,50} (just as an example, the values aren't linearly spaced) to do some calculations. But what I need to know is the index of the last number which has a sign (is negative).
How can I do that? Sadly there is no function like IsSigned(..)=true.
If you want to do it without a loop
Sub test()
Dim dataset1 As Variant
dataset1 = Array(-9.5, -7, -5.25, -3, -1.1, 0, 1, 5, 20, 50)
Debug.Print UBound(Filter(dataset1, "-")) + 1
End Sub
My solution looks like this:
'Find last signed value
For i = LBound(concarraycleared, 2) To UBound(concarraycleared, 2)
If concarraycleared(2, i) < 0 Then
LastSignedIndex = i
Else
Exit For
End If
Next i
Couple of limitations: Array needs to be vertical, can only find the last signed value one time, values need to be sorted in ascending order. You can not reverse search order. This is pretty specific solution tailored to my problem, so the above solution should be regarded fist.

Unique values in Excel

I need to get a value which has the maximum number of occurrences in the unique data set from a big column based on a condition. I just need one value and not the array.
See below the example data that I am working with. I have done it in MATLAB but want to know it in Excel.
So in the above data for example, I want to get the unique values for lanes based on the value of #safea. So if #safea=102 then unique values of lanes=(2,3,1). But I want the value from these set of data which has maximum number of occurrences. In this case it is 2 because 2 has come up 5 times whereas 3 has come up once and 1 has come up as only 1 time.
Another example:
If I select #safea as 162, then the number of unique values in lanes (5 and 4) but 5 has come up 4 times and 4 has come up as only 1 time so the final answer that I want is '5'.
If you don't mind using VBA, I've devised a Function you can use for what you want. Given the #safea values are in column A and the lane values are in column B, you can use this:
Function MODEIF(criteria As Integer) As Integer
Dim count As Integer
count = Application.WorksheetFunction.CountA(Range("A:A"))
Dim list() As Integer
Dim size As Integer
size = 0
Do While count > 0
If (Range("A" & count) = criteria) Then
ReDim Preserve list(size)
list(size) = Range("B" & count)
size = size + 1
End If
count = count - 1
Loop
MODEIF = Application.WorksheetFunction.Mode(list)
End Function
Just put this Function in a Module, go to the spreadsheet, and type =MODEIF(102) or whatever #safea value you want the mode for and it will give you the answer.
You could also use this worksheet function to get a conditional MODE:
=MODE(IF(**your #safea value here**=$A$2:$A$22,$B$2:$B$22))
This is an array formula. Confirm entry by pressing Ctrl+Shift+Enter (not just Enter).

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