MINUS operation on Array elements - excel

I have an Array say A=(11,23,32,44,56,88,55,14,78,79) And B=(44,56,88,55,14) .Now using VBScript can I perform Set operation MINUS to get an other output say C=(11,23,32,78,79)?
Array A and B can be considered also two Excel columns.
Don't want to use any Looping technique.
Please help
Thanks,

No, vbs or vba cannot directly do a minus operation on two array ( no build-in function )
You must use loops
and here is a good reference for array operations in vba http://www.cpearson.com/excel/vbaarrays.htm

Perhaps it's not a surprise that Dictionaries are the VBScript tool to implement (fake?) sets and operations on them. See this Set demo.
BTW: If you have to deal with more than one thingy, you'll have to loop or ask someone else to loop for you. Insisting on "no loop, please" makes no sense. If 'it works', you may optimize by replacing multiple loops (n x m .. x z) by lookup tables or pre-computations, but you won't understand the problem, if you don't think of loopings.

You can do that in Excel vba if u have named ranges Acol Bcol
Range("C3:C10").FormulaArray = "=Acol-Bcol"

Related

Excel's LAMBDA with a "kind of" composite function

Ever since I learnt that Excel is now Turing-complete, I understood that I can now "program" Excel using exclusively formulas, therefore excluding any use of VBA whatsoever.
I do not know if my conclusion is right or wrong. In reality, I do not mind.
However, to my satisfaction, I have been able to "program" the two most basic structures of program flow inside formulas: 1- branching the control flow (using an IF function has no secrets in excel) and 2- loops (FOR, WHILE, UNTIL loops).
Let me explain a little more in detail my findings. (Remark: because I am using a Spanish version of Excel 365, the field separator in formulas is the semicolon (";") instead of the comma (",").
A- Acumulator in a FOR loop
B- Factorial (using product)
C- WHILE loop
D-UNTIL loop
E- The notion of INTERNAL/EXTERNAL SCOPE
And now, the time of my question has arrived:
I want to use a formula that is really an array of formulas
I want to use an accumulator for the first number in the "tuple" whereas I want a factorial for the second number in the tuple. And all this using a single excel formula. I think I am not very far away from succeeding.
The REDUCE function accepts a LET function that contains 2 LAMBDAS instead of a single LAMBDA function. Until here, everything is perfect. However, the LET function seems to return only a "single" function instead of a tuple of functions
I can return (in the picture) function "x" or function "y" but not the tuple (x,y).
I have tried to use HSTACK(x,y), but it does not seem to work.
I am aware that this is a complex question, but I've done my best to make myself understood.
Can anybody give me any clues as to how I could solve my problem?
Very nice question.
I noticed that in your attempts you have given REDUCE() a single constant value in the 1st parameter. Funny enough, the documentation nowhere states you can't give values in array-format. Hence you could use the 1st parameter to give all the constants in (your case; horizontal) array-format, and while you loop through the array of the 2nd parameter you can apply the different types of logic using CHOOSE():
=REDUCE({0,1},SEQUENCE(5),LAMBDA(a,b,CHOOSE({1,2},a+b,a*b)))
This way you have a single REDUCE() function which internal processes will update the given constants from the 1st parameter in array-form. You can now start stacking multiple functions horizontally and input an array of constants, for example:
=REDUCE({0,1,100},SEQUENCE(5),LAMBDA(a,b,CHOOSE({1,2,3},a+b,a*b,a/b)))
I suppose you'd have to use {0\1} and {1\2} like I'd have to in my Dutch version of Excel.
Given your accumulator:
Formula in A1:
=REDUCE(F1:G1,SEQUENCE(F3),LAMBDA(a,b,CHOOSE({1,2},a+b,a*b)))

Evaluate long string (>255 characters) as array

So I quite often find myself doing tasks on Excel which involve evaluating a text string as an array. Generally speaking I just use this:
Function EVAL(Ref As String)
EVAL = Evaluate(Ref)
End Function
So the formula will be, for example:
=EVAL("{"&CHAR(34)&SUBSTITUTE(TEXTJOIN(";",TRUE,MID(Index[Industries],2,LEN(Index[Industries])-2)),";",CHAR(34)&";"&CHAR(34))&CHAR(34)&"}")
The cells in this example will have contents like:
;Automotive;Rail;Energy;
;Automotive;Rail;
;Energy;
;Automotive;Aerospace;
(As it happens this is the precise problem I'm stuck on right now, though it has come up in different ways in the past.)
This has worked for me in the past, but I've been running into difficulties lately.
I have come to the conclusion it isn't working because application.evaluate, it turns out, has a character limit of 255. I've seen examples of VBA tricks to bypass this for text strings that are formulas rather than arrays, but copy-pasting those they don't seem to work for when I'm using it to interpret a text string as an array rather than as a formula.
Is there some trick to get this to work? (Or, indeed, is there some alternative method to achieve this altogether?)
Right, as per my comments, if you are using ms365, you could avoid your workbook to be xlsm just because you need to split values into an array. Make use of what is available with native functions, for example:
Formula in C2:
=TEXTSPLIT(CONCAT(A1:A4),,";",1)
Formula in D2:
=FILTERXML("<t><s>"&SUBSTITUTE(CONCAT(A1:A4),";","</s><s>")&"</s></t>","//s[node()]")
Note 1: As per time of writing you'd need to enable the BETA-channel to gain access to TEXTSPLIT(), and if I recall correctly your version (2203) is allowed to start using this function. Just google how to get access and update your Excel.
Both options can obviously be nested inside the UNIQUE() function.
Note 2: If at any point CONCAT()'s limits are reached (32767 characters, thanks #ScottCraner), maybe you can avoid using that with help of the lambda's helper function REDUCE():
=TEXTSPLIT(REDUCE("",A1:A4,LAMBDA(a,b,a&b)),,";",1)
Note 3: In case you can't update your Excel just yet, and you wonder how to use FILTERXML(), don't mind me refering you to another post I wrote a while back here.

VBA loop preference

I am currently trying to optimize a VBA code with extreme execution time (56 hours and more on high end PC). The main problem is nested loops (up to 8) due to complicated iterative calculations and referencing ranges in formulas.
I have two questions:
1)
What loops are most preferred in VBA (based on their hardware strain for lack of better word)
2)
Is there a way to reference variable range of cells in a formula? For example in formula:
=AGGREGATE(15,6,SQRT((R2C10:R500000C10-RC[10])^2+(R2C11:R500000C11-RC[11])^2+(R2C12:R500000C12-RC[12])^2),1)
I am referencing relative cell: "R500000C10". There are two main issues: For one, the half milion cells might not capture all data - though in most cases there is less active cells than that, in same cases that might be an issue. Second, it takes forever to scan through so many cells (same reference is used in multiple of VLOOKUPs).
The first issue could be solved by referencing the whole column, but that makes the second problem worst.
I would like to reference it in a similar way that xlDown works:
Range().End(xlDown).Select
The problem there is I would need to reference it within the Active.Cell.FormulaR1C1. Is there a way to do that?
Thanks!
Well you wrote that you have a code with 8 loops and try to optimize it maybe you can edit and put part of that code, because your description is very general, however, with information that you put i speculate that about your point
1)it depend what do you want to do? because each "loop" have their own use for specifyc scenaries
2)there are tricks to do that but all depend what are you trying to do and why you want to use .formulaR1C1
again im speculating but you can try tu separate your loops in indenpendent function, and maybe you are putting a formula inside cells, and question is why? you can create functoins and Sub in your VBA code and do your "extrem execution" without use xtra "resours"

Excel concatenation logical conditions in IF statement

How do I concatenate several conditions in Excel in the IF statement? I want to compare values in 2 different columns but mith more than 1 condition!. IF (condition 1,condition2 ; truevalue;) i dont know the sintaxis for this!
If you use purely native worksheet functions, you have to nest your if statements. It's far from ideal:
=if(condition1,X,if(condition2,Y,if(condition3,Z,A)))
Is like saying:
if (condition1) then X
else if (condition2) then Y
else if (condition3) then Z
else A
You can also define a User Defined Function (UDF) using VBA, but that has some disadvantages associated with it. It adds a lack of transparency for those who don't use VBA. It also makes your workbook a little more "suspicious" since it has embedded macros, which is a turn off for some.
Depending on how complex your conditions are, a UDF still may be the way to go.
Post some real pseudo-code to help identify which side you fall on.

How to evaluate typed-out formulas in Excel

If I type the formula 1/4*pi()*($A$1)^2 as a string in a cell and assuming I have a value in $A$1, I use the following VBA function in a third cell to evaluate the formula:
Public Function E(byval TextFormula as String) as Variant
E = Evaluate(TextFormula)
End Function
Is there a way to use math characters like •, √, ¼, π, ², etc. so that my typed-out formula looks more agreeable? Even translate '[' and ']' as '(' and ')'. I can just iterate through an array replacements using REPLACE() function for the simple characters but what about the extended characters like π?
For the really sharp macro'ers...
What about showing intermediate steps (iterations) as in (2*3) + (2.5*4) evaluates to 6 + 10 in the first iteration and then 16 in the next iteration. Asside: I would want the iterations to stop just before each set of addings/subtractings because I sometimes like to know what the relative magnitudes of the individual evaluated terms are to see what part of my formula is controlling the result.
And for the mega-genius ones...
What about mixed units? Such as typing out 560{lbs}/[1.23{m}*3.4{'}] and getting my result in ###{psf} as an example. I thought that the unit could be delineated by the underscore such as 34_kN but I think a start and end delineation is required for compound units like 34{kN/m^2}. There would need to be a way to force the output to a desired unit (ie. mm instead of in) like maybe setting up your desired units ahead in your sheet and then it would at least try to convert to one of those units. I think at this stage you will be charging me for the code;)
I like using Excel for my engineering calculations because I only use simpler formulas (no calculus!) and I don't want to constantly switch between Excel and Mathcad apps but use only one.
Shawn
Those are tall orders. The following sub might give you an idea for your first question:
Sub test()
Dim R As Range
Set R = Range("A1")
R.Value = "A = pr2"
R.Characters(5, 1).Font.Name = "Symbol"
R.Characters(7, 1).Font.Superscript = True
End Sub
Run it an then look at the contents of A1
As far as your second question goes - sure you can do it, but you would need to write a full-fledged expression parser. Writing one from scratch is fairly involved (at least a couple hundred lines of code) and is probably best done by using classes to create a custom tree data type then writing a recursive descent parser to parse strings into expression trees. Doable, though I have neither the time nor the inclination to do so.
I'm not quite sure what you are driving at with your last question, though my gut reaction is that it is easier than your second question since no real parsing is required and it is easy enough to create a dictionary of conversion factors.

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