Solved: Re: In a collection, how to create a column where ...

PowerGirl · ‎11-27-2020

Hello everyone! I really, really need your help.

I need to calculate the total annual spend and the net present value for different projects. For that I have the following information in a table (sample info):

Annual average volume 4000

Program life time in years 8

Cost reductions 3% in 3 years 2% in 2 years

Piece price 1.50

The Rate% for the Present value calculation will be given in an input field in the app

I attached the table I need to create/simulate to be able to perform these calculations in excel. The explanation is as follows:

1. First I need to create a table with number of items from 0 to program life time in years . I store an index in the first column.

2. For column 2 I need to transform the text in the column "Cost reductions" to a column stating the year 0 no cost reductions, the next three years a reduction of 3% and the next 2 years a reduction of 2%

3. For column 3 I need to calculate the piece price for each year =Piece price of the previous year * (1-cost reduction of this year) (for the year 0 the piece price will be the one given in the item)

4. For the Total Spend column I need to multiply the calculated piece price of this year * annual average volume. The sum of this column will give me the Total Annual spend that I am looking for.

5. For the Present Value column I need to divide the total spend / (1-rate%)^ThisItem.year (the first column). The sum of this column will give me the Present Value

Until now I have created a collection as follows:

ForAll(Sequence(Value(Last(FirstN(Split(ThisItem.CostReduction, " "),3)).Result),1),Collect(Reduction1,{ReducPercentage:Last(FirstN(Split(ThisItem.CostReduction, " "),1)).Result,AnnualVol:LookUp(QBOM,QBOMIDinQBOM=ThisItem.QBOMIDinCBD1).TotalAnnualAvgCmpVolume,Index:CountRows(Reduction1)+1,PiecePrice:Left(Label64_1.Text,Find(" ",Label64_1.Text)),Spend:0}));
ForAll(Sequence(Value(Last(FirstN(Split(ThisItem.CostReduction, " "),7)).Result),1),Collect(Reduction2,{ReducPercentage:Last(FirstN(Split(ThisItem.CostReduction, " "),5)).Result,AnnualVol:LookUp(QBOM,QBOMIDinQBOM=ThisItem.QBOMIDinCBD1).TotalAnnualAvgCmpVolume,Index:CountRows(Reduction2)+CountRows(Reduction1)+1,PiecePrice:Left(Label64_1.Text,Find(" ",Label64_1.Text)),Spend:0}));
ForAll(Sequence(Value(Last(FirstN(Split(ThisItem.CostReduction, " "),11)).Result),1),Collect(Reduction3,{ReducPercentage:Last(FirstN(Split(ThisItem.CostReduction, " "),9)).Result,AnnualVol:LookUp(QBOM,QBOMIDinQBOM=ThisItem.QBOMIDinCBD1).TotalAnnualAvgCmpVolume,Index:CountRows(Reduction3)+CountRows(Reduction2)+CountRows(Reduction1)+1,PiecePrice:Left(Label64_1.Text,Find(" ",Label64_1.Text)),Spend:0}));
ForAll(Sequence(Value(Last(FirstN(Split(ThisItem.CostReduction, " "),15)).Result),1),Collect(Reduction4,{ReducPercentage:Last(FirstN(Split(ThisItem.CostReduction, " "),13)).Result,AnnualVol:LookUp(QBOM,QBOMIDinQBOM=ThisItem.QBOMIDinCBD1).TotalAnnualAvgCmpVolume,Index:CountRows(Reduction4)+CountRows(Reduction3)+CountRows(Reduction2)+CountRows(Reduction1)+1,PiecePrice:Left(Label64_1.Text,Find(" ",Label64_1.Text)),Spend:0}));
ClearCollect(Reduction,Reduction1,Reduction2,Reduction3,Reduction4); Clear(Reduction1);Clear(Reduction2);Clear(Reduction3);Clear(Reduction4);

as you can see the Piece Price the annual spend are not yet calculated.

My questions:

Is there a better way to get the cost reductions into the collection (maybe dynamically)?

How can I create the column piece price? (I have tried with For All, Sequence, Patch, ThisRecord.Index-1 but I can not find the right combination and I can not patch in the same source as the for all)

Is there a way to make a For All inside of a For All to make the calculation of the Total Annual Spend and the Present Value without creating a collection or how would you recommend me to do these calculations?

Every help is welcome!

RandyHayes · ‎12-01-2020

@PowerGirl

Okay...I got a chance to go over this some more.

So, it's a relatively complex formula as you have multiple aspects of variation going on why calculating on each.

In my sample setup, I have 5 TextInput controls. One for the Annual Volume, one for the Program Years, one for the Cost Reduction formula, one for the Piece Price and one for the Rate.

Unfortunately, doing all of this without a collection is not possible (as I had hoped we could eliminate) because we (during the calculation) need to refer back to a prior value while at the same time generating a new prior value. The only way I know to do this is with the collection as you can add a record and refer (Lookup) at the same time on the same collection.

I have the formula below on a Button and then have Two labels on my sample setup.

One label has a Text property of : finalAmortResult.AnnualSpendTotal

and One has a Text property of : finalAmortResult.AnnualSpendAmortization

I did not do any rounding on the final numbers because I found that your example table did calculations on NON-Rounded numbers and that was significant.

When the final numbers are rounded, they are off by $0.01. Since I don't know the original formulas you had in your spreadsheet, I would assume there was something significant there for rounding.

Based on the sample you provided, the formula returns the exact numbers you highlighted as what you need. The formula is flexible to allow for expansion of the Cost Reduction formula as we mentioned in prior posts - as long as they observe the <percentage> in <X Years> format.

And...here is the formula. I commented most of it as you might not be familiar with all of the aspects of it.

Clear(colAmort);

// At the Outer Level we are defining scope variables for input the the formula.  The controls in this With should be changed to reflect controls in the app
With({_CostReductionString: txtCostReduction.Text,
      _years: Value(txtYearsInSchedule.Text),
      _piecePrice: Value(txtPiecePrice.Text),
      _pieceQuantity: Value(txtPieceAmount.Text),
      _annualSpend: 1+(Value(txtAnnualSpend.Text)/100)},
    // First outer level in With - define a table of periods, there will be one record for each rate change and this scope variable will serve as the primary table for the final calculation
    With({_periods: 
        // In this With (2nd outer level) - define the series for each rate change period.  This will define the starting values, percentage rates, and start and end 
        With({series:
            // Perform a regular expression on the cost reduction series and gather up to 4 years of percentage rates 
            // (note: regex can be expanded for more years as needed)
            // all of the Match information will be in _cr table
            With({_cr:Match(_CostReductionString,  
                  "^(?:(?<p1>\d+)%)?\D*(?:(?<years1>\d+))?\D*(?:(?<p2>\d+)%)?\D*(?:(?<years2>\d+))?\D*(?:(?<p3>\d+)%)?\D*(?:(?<years3>\d+))?\D*(?:(?<p4>\d+)%)?\D*(?:(?<years4>\d+))?")},
                // Create a table of records with information from the matches.  
                // Each record will have the Period sequential value, the Sequence Number, the percent from the cost reduction string and the years from the string.
                // Filter out empty years
                Filter(
                    // note: Sequence - half of the count of matches (as each has a percent and a year(s)), start at 1, skip every other number
                    ForAll(Sequence(CountRows(_cr.SubMatches)/2, 1, 2),
                        If(!IsBlank(Last(FirstN(_cr.SubMatches, Value)).Value),
                            {Period: Value,
                             Seq: (Value+1)/2,
                             Percent: Value(Last(FirstN(_cr.SubMatches, Value)).Value),
                             years: Value(Last(FirstN(_cr.SubMatches, Value+1)).Value)
                            }
                        )
                    ),
                    years>0
                )
           )},

            // Create the series table.
            AddColumns(
                // create table from the sequence of all the series items (from the _cr).  
                // Adding two records to the series - one for starting period and one for ending period.  
                // It is assumed that year 0 is always the starting year with NO percentage change.
                // Start sequence at zero for year zero
                ForAll(Sequence(CountRows(series)+2,0),
                    // define a series year scope variable to calculate the starting year of the period
                    // get the sum of the prior period years and subtract out the years for the current period (add one to set bound)
                    With({sy:Sum(Filter(series, Seq<=Value), years) - Sum(Filter(series, Seq=Value), years)+1},
                       // Create record with sequential period number, start and end year of period, percent rate during period and starting Value (only for year 0)
                       {period:Value, 
                        start: If(Value=0, 0, sy), 
                        end: If(Value=0, 0, If(Value>Last(series).Seq, _years,  sy + LookUp(series, Seq=Value, years)-1)), 
                        pcnt: 1-(Coalesce(LookUp(series, Seq=Value, Percent),0)/100),
                        startValue: If(Value=0, _pieceQuantity * _piecePrice, 0),
                        amortRate: If(Value=0, 1, _annualSpend)
                       }
                    )
                ),
                // add a span helper column
                "Span", end-start+1
            )
        )},  //end of _period definition


        // throw away loop - loop through all the _periods in sequence. 
        ForAll(Sequence(CountRows(_periods)),
            // Grab the period record that corresponds to the current sequence
            With({_periodRec: Last(FirstN(_periods, Value))},
                // Grab the prior sequence value from the prior record of the collection colAmort we are building.
                // If we are at 0 (the year that holds the starting value) use that startValue from the current period record (it will be year 0)
                With({_priorValue: If(_periodRec.startValue=0, Last(FirstN(colAmort, CountRows(colAmort))).EndValue, _periodRec.startValue)},
                    // Preform the calculations on each item in the sequence for the amounts
                    With({_spanCalculations: ForAll(Sequence(_periodRec.Span), {seq:Value, amt:_priorValue * (_periodRec.pcnt^Value)})},
                        // Collect a new record with the main calculations
                        Collect(colAmort,
                            {   
                            // Total value for the entire period
                            // Sum all of the amortized values for each year in the current period based on the period percentage and the opening value
                            // Amortization formula is : value * (percentage ^ YearNumber)
                            PeriodTotal: Sum(_spanCalculations, amt), // Value),
                            // Calculate the ending amortized value (used for the next period)
                            EndValue: _priorValue * (_periodRec.pcnt^_periodRec.Span),
                            // Calculate the amortized values based on the period amounts, adjusting for the year in the span
                            AmortTotal: Sum(ForAll(_spanCalculations, amt / (_periodRec.amortRate ^ (seq + _periodRec.start - 1) )), Value)
                            }
                        )
                    )
                )
            )
        )    
    );

);

    // For convienience - a final record:
    Set(
    finalAmortResult, 
        {AnnualSpendTotal: Sum(colAmort, PeriodTotal),
         AnnualSpendAmortization: Sum(colAmort, AmortTotal)
        }
    )

I hope this is helpful for you. Enjoy!!

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View solution in original post

RandyHayes · ‎11-27-2020

@PowerGirl

As I read through your post and also your formula, I believe your bigger challenge seems to be how to get the 3% in 3 and 2% in 2 year values. My question will be this, for the CostReduction column, will your format always be like you demonstrate? Are there other factors of that column that should be know? (i.e. surprises like - some column may contain nothing, or some special text)

_____________________________________________________________________________________
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PowerGirl · ‎11-27-2020

@RandyHayes

For now this can look empty, with one, two, three or four different discounts in different years. That is why I included 4 For All s. This way I could get a table, but then how to calculate the right price per year. That is my next challenge.

RandyHayes · ‎11-27-2020

@PowerGirl

If you are aiming to get the two values at the bottom of the example you gave, then there really is no need for collections for any of this. My concern with that approach would be how are you going to handle no discounts, 1, 2, 3 or 4 discounts? You're going to need a formula not a structure so much.

That said, that is why I was focused on the cost reduction text - that is where it is all going to hinge. Can you give me an example of a 4 value cost reduction (i.e. 4 different percent's)?

_____________________________________________________________________________________
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PowerGirl · ‎11-27-2020

@RandyHayes
This would look like: 3% in 2 years 2% in 2 years 1.5% in 2 years 0.5% in 2 years

in the future they might put only something like 3x3 and I would need to change it to the “standard” to calculate it or allow them only to use this format

poweractivate · ‎11-27-2020

@PowerGirl

Your question seems to presume collections and the complex nested ForAll formulas are a specific set of preconditions to a viable end solution in the Power Apps Canvas App. You did attempt it though and also you did post specific details about what you tried, which is much appreciated.

We'd advise in this case you start with the end objective level rather than the actual implementation detail and indicate this in the next reply. We think this may also be related to the reason that @RandyHayes is asking you for examples of the columns in multiple replies, etc.

So that is why we think that instead, we believe you should just give an example of the end result. For example, instead of "Formulas" it should just be what rows you would expect for the real world scenario usage. Yes, it would be useful for you to include the varying possibilities of the percentages being there or not being there, etc. however we'd like version where there is not the implicit presumptions of the implementation paradigms, as this version by itself is not so easy for us to advise you on. @RandyHayes questions so far are just part of the evidence of this being the case here.

1) Because the screenshot depiction and also the original post appears to make presumptions about certain paradigms, we are unsure how to help you with it. Instead, we'd advise you provide a depiction of the end result you'd like to see, pretending you did not know Power Apps Canvas Apps evenexists, then this way we might be able to better help you with a more comprehensive picture of what you would like as the actual solution, then advise you from that vantage point.

2) We would like to ask you if one presumption is correct or not. Is Power Apps Canvas App your specifically preferred or required methodology of the implementation for this scenario? We are presuming yes based on the original post. However, if the presumption is incorrect, please indicate this in the next reply. It is highly likely that Power Apps Canvas App has a very good way of doing what you are asking, we are asking this in case after we check it that one or more other components of Power Apps, instead of or even in addition to the Power Apps Canvas App would end up being more appropriate for this case (but in order for us to determine this with a more complete picture of your scenario, please see #1 above as well).

PowerGirl · ‎11-27-2020

Thank you for your response @poweractivate . 1. Response: You are right, I showed what I am working on already to try to get an answer. The original problem is as follows. I

need to calculate the total annual spend and the net present value for different projects. For that, I have the following information available (sample info):

Annual average volume 4000

Program life time in years 8

Cost reductions 3% in 3 years 2% in 2 years

Piece price 1.50

Rate for NPV 10%

In excel there is a formula to get the NPV, but I can’t find it in power apps. If I would have to calculate this in excel I would have used a similar table as attached.

how can I calculate these two values (total annual spend and net present value) and display this in power apps? I need to compare this values from different selected projects in a gallery and the calculation of the piece price is also done in the app.
2. Response: in the project we are using Power Apps, power automate and power BI. I thought that since the calculation of the piece price is done in the app I could find a way to do it also here, but I am open to suggestions. I just need to show the two values in the app in a gallery to be able to compare them

I hope this is clearer. Let me know if you need more information.
Thank you for your feedback

PowerGirl · ‎11-27-2020

Using a formula only would be awesome. Would you have any suggestions of this formula?

poweractivate · ‎11-27-2020

@PowerGirl

If you are using Power BI this is much easier and straightforward to do there, as Power BI is a better fit for this type of thing. Here's just one of likely many examples to do it in Power BI (community.powerbi.com)

Then you can connect to Power BI from Canvas App (docs.microsoft.com)

You can even instead Embed a Canvas App inside a Power BI report with context passed into the Canvas App from Power BI Re... (e.g. when something is selected in Power BI, pass it into the Canvas App and make the Canvas App show something or present a call to action to do something)! Of course at that point you might want to consider just using the report. However, embedding a Canvas App inside a Power BI Report allows you to do things like interactive experiences, etc. that cannot be done from Power BI without the embedded Canvas App.

In case you must absolutely do it from Canvas App only with no other component being used such as Power BI, then we could try to check more into it if you want. If it has to be in the Canvas App only we may still be able to help, but the solution will be probably more complex to do in the Canvas App only.

PowerGirl · ‎11-28-2020

To be honest I am not very familiar with Power BI. If there is a solution on Power Apps I would prefer it. Anyway I will have a look on the links you send me and see how it works.

We have tried before to calculate the total annual spend in Power BI (and with that we could use the NPV formula) with the same input and could not figure out how to get the right piece price based on the column of Cost reduction. Would you have any suggestions on what to use? Would this be a calculated column? What formula to use? We have the same inputs in Power BI.