Recursive calculation

[zivhimmel]

Hi,

How can I do the following ?

First day - Column A = 100

2nd day and every day that follows, column A=yesterday's value of column A X column B.

Thanks !

[v-qiuyu-msft]

Hi @zivhimmel,

Would you please share some sample data and desired results so that we can try to test it?

Best Regards,
Qiuyun Yu

[zivhimmel]

Thanks @v-qiuyu-msft.

Basically what I am trying to do is like compund interest.

Imagine you have a 100 dollars. Each day you get 1% on your 100 so in day 2 you have 101, In day 3 you have 102.01, In day 4 you have 103.0301 etc.

Now, let's change it a bit - 1% a day is not fixed. It can change. On one day it's 1%, the next day it's zero, the next day it's 2%.

You need to be able to calculate your return over time. After 3 or 300 or 4562 days, for any given date range.

Example of dataset :

date,interest

11/1/2016, 0.01

11/2/2016, 0.01

11/3/2016, 0.005

11/4/2016, 0

11/5/2016, 0.02

So, based on the above dataset, if I want to calculate the return for the entire period, it would be like that :

100*(1+0.01)*(1+0.01)*(1+0.005)*(1+0)*(1+0.02)

If I want to calculate the return in the date ramge 2/11-4/11 :

100*(1+0.01)*(1+0.005)*(1+0)

I hope it makes sense.

Please let me know if you need additional information.

Any help is much appreciated. Thanks !

[OwenAuger · Accepted solution]

@zivhimmel

Following from other replies, you basically need to calculate the cumulative product of your 'growth factors'.

Gerhard Brueckl's blog (link above) had a method using summing logarithms, then mentioned that you can now use PRODUCTX.

Here are two examples using PRODUCTX in a calculated column. You could adapt this to a measure if that makes sense as well.

[askelton]

@OwenAuger

Sorry this is quite an old post, however I saw you were online and this applies to what I am working on now.  I'm fairly new to PowerBI and you said this could be adapted to a measure if needed.  Would you mind explaining how?  When I try I get

"A single value for column 'Date' in table 'Data' cannot be determined.  This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result."

This is my overall problem i'm working on.  

https://community.powerbi.com/t5/Desktop/Converting-quot-Measure-gt-Calculated-table-gt-Calculated-C...

[zivhimmel]

Hi @OwenAuger, thanks allot for taking the time and answering.

I don't see however how it solves the compound interest problem.

I'm missing the part where you multiply the day's Growth Factor with yesterday's.

If we had 1 dollar and the growth factor is 1%, then we now have 1.01.

The next day, if the growth factor is again 1%, then we now have 1.021.

I need a way to calculate it(column C below) :

Thanks !

[zivhimmel]

I apologize, @OwenAuger, your solution is perfect. I read it too early before cofee probably.

Scratch that.

Thanks !

[CheenuSing]

Hi @zivhimmel

The link

http://blog.gbrueckl.at/2015/04/recursive-calculations-powerpivot-dax/

may be helpful. Check it out. If it solves your issue please give KUDOS.

Cheers

CheenuSing

[zivhimmel]

Thanks @CheenuSing, I've actually seen it before posting but couldn't extract exactly what I need from it,

I'll give it another try.