How to weigh counts based on repeat values?

[NAMLANI]

Hi,

I have the following Table1:

Name	ID
John	111
John	222
Jane	333
Jane	111
Jane	444

I get the counts of the IDs for each name like below (COUNTX('Table1', [ID])):

Name	Count of ID
John	2
Jane	3

I'd like to weigh the counts of any matching values in the ID column by .5. So since John and Jane both have a 111, that count is now .5, resulting in:

Name	Count of ID
John	1.5
Jane	2.5

I can't figure out how to write a function for this. Appreciate any assistance!

[Daryl-Lynch-Bzy]

HI @NAMLANI  , @Greg_Deckler - I was going to suggest the following:

New Measure =
SUMX (
    ADDCOLUMNS (
        'Table',
        "ID Count",
            VAR _ID = 'Table'[ID]
            RETURN
                CALCULATE (
                    COUNTA ( 'Table'[ID] ),
                    REMOVEFILTERS ( 'Table' ),
                    'Table'[ID] = _ID
                )
    ),
    DIVIDE ( 1, [ID Count] )
)

[Greg_Deckler · Accepted solution]

@NAMLANI Perhaps something like this:

Measure = 
    VAR __Name = MAX('Table'[Name])
    VAR __WeightTable = SUMMARIZE(ALL('Table'),[ID],"__Weight",1/COUNTROWS('Table'))
    VAR __Table = ADDCOLUMNS('Table',"__Score",MAXX(FILTER(__WeightTable,[ID] = EARLIER('Table'[ID])),[__Weight]))
RETURN
    SUMX(__Table, [__Score])