topic Re: Creating a delta column in Discussions

Creating a delta column

jearls11 — Sat, 10 Jun 2023 23:29:28 GMT

Hi folks,

I am trying to create a delta column.

the difference is between mean(normalised) - mean(normalised of the "MATCHED" product)

I tried the lag function but this doesnt work as no date.

Would I have to create a new column "Matched_Value" and set all row values to the Same as the MATCHED value

then create my delta = Mean(no...) - Matched...

Re: Creating a delta column

txnelson — Thu, 29 Apr 2021 16:09:00 GMT

This formula is an easy way to do what you want

If( Row() == 1,
	matched = :"Mean(Normalised)"n[(Current Data Table() << get rows where( :PRODUCT == "MATCHED" ))[1]]
);
:"Mean(Normalised)"n - matched;

Re: Creating a delta column

jthi — Thu, 29 Apr 2021 16:09:09 GMT

You won't have to create such a column, but it is quite easy way to solve this.

You could create formula which would use for example Loc() to get the index of MATCHED PRODUCT and then use that to get value from Mean(Normalized) column. For example something like this:

:Name("Mean(Normalised)") - :Name("Mean(Normalised)")[Loc(:PRODUCT << get values, "MATCHED")[1]]

I suggest you take a look in the formula menu and see what subexpressions return or break the example into multiple formulas to understand properly what it does (and for example why there is [1] after Loc).

Re: Creating a delta column

jearls11 — Thu, 29 Apr 2021 17:05:57 GMT

Thank you guys for both formulas