What does Σ mean in a formula!!!!

[sxhall]

Hi,

I've dabbled with Excel for years and have come across this symbol, Σ, when Googling for a solution to exclude colums within the CHOOSECOLS function.

This is the solution I am using it in to combine four tables in to one while excluding certain column numbers and allowing a sort to be applied...

=SORT(VSTACK( CHOOSECOLS(Rota_T1,LET(Σ,SEQUENCE(382),FILTER(Σ,ISERROR(XMATCH(Σ,{2,3,5,6,7,8,10,11}))))),CHOOSECOLS(Rota_T2,LET(Σ,SEQUENCE(382),FILTER(Σ,ISERROR(XMATCH(Σ,{2,3,5,6,7,8,10,11}))))),CHOOSECOLS(Rota_T3,LET(Σ,SEQUENCE(382),FILTER(Σ,ISERROR(XMATCH(Σ,{2,3,5,6,7,8,10,11}))))),CHOOSECOLS(Rota_T4,LET(Σ,SEQUENCE(382),FILTER(Σ,ISERROR(XMATCH(Σ,{2,3,5,6,7,8,10,11})))))),SWITCH(C154,"Team",2,"Colleague Name",1,"Shift Pattern",3,1),1)

In the above I've combined LET to exclude some columns inside the Function CHOOSECOLS, which inturn I've inserted in to VSTACK to combine the tables, all wrapped in SORT to define the sort order, with a SWITCH at the end based on the named choice to refernce a column number to sort the list by.... and breathe!!!!!

Symbol Σ is used in the LET and FILTER function and have never seen it used before but it works! What is the Σ symbol doing in the above formula? The piece I lifted the web is...

=LET(Σ,SEQUENCE(382),FILTER(Σ,ISERROR(XMATCH(Σ,{2,3,5,6,7,8,10,11})))))

Hope this is the right forum as I have a solution, this is just a question.

Sxhall

 

[RoryA]

It's just a variable name. It could have been called anything but some people like to use symbols.

 

[sxhall]

RoryA,

Thanks for coming back so soon. It's obvious now you've said it and I can see how it works with LET and then with FILTER.

I'll leave it in there as it will baffle my colleagues, if it baffled me. Will only make me look like more of an Excel wizzard

Sxhall