How to fill in a matrix column with previous values

[hsw_1]

Hi

I am relatively new to Power Bi desktop and trying to figure out how to backfill a matrix visual with previous column values (ratings).  Please can anyone advise how to do this? thank you

My matrix looks like this

	Matrix Visual
	03-Jan	29-Jan	14-Mar	11-Apr	24-Apr
Vendor1		A+		A-
Vendor2			B-		B+
Vendor3			A+		A-

and I want to fill in the missing values (in bold)

	03-Jan	29-Jan	14-Mar	11-Apr	24-Apr
Vendor1		A+	A+	A-	A-
Vendor2			B-	B-	B+
Vendor3			A+	A+	A-

My data tables are as follows:

Tables
	Rating	Vendor id	Rating date	Rating value
		1	29-Jan	A+
		1	11-Apr	A-
		2	14-Mar	B-
		2	24-Apr	B+
		3	14-Mar	A+
		3	24-Mar	A-
Vendor	Vendor	Vendor id	Vendor Name
		1	Vendor1
		2	Vendor2
		3	Vendor3

[hsw_1]

Thanks for this @tamerj1   However, I couldn't get it to work for me.  It seems that because I don't have a row in the Rating table for every Vendor/RatingDate combo, then it will not assign a measure value for those cells.  I've also tried creating a calculated table in AAS with just the Ratingdate values but this doesn't seem to have helped either.   Not sure what else to do apart from a backend fix to populate the data manually - seems like it shouldn;t be this difficult though

[tamerj1]

@hsw_1 

Better to use a dim date table. In this case you can populate any value as the matrix would be sliced by two dim tables. 

[tamerj1]

@hsw_1 

Maybe I'm over complicating, not even sure it will work 

Rating Measure =
VAR CurrentDate =
CALCULATE ( SELECTEDVALUE ( Rating[Date] ), ALL ( Vendor ) )
VAR PreviousDate =
MAXX (
FILTER (
CALCULATETABLE ( ALL ( Rating[Date] ), ALL ( Vendor ) ),
Rating[Date] < CurrentDate
),
CurrentDate
)
VAR CurrentVendor =
CALCULATE ( SELECTEDVALUE ( Vendor[Vendor Name] ), ALL ( Rating ) )
RETURN
IF (
ISEMPTY ( Rating ),
CALCULATE (
MAX ( Rating[Rating Value] ),
REMOVEFILTERS (),
Vendor[Vendor Name],
CurrentVendor,
Rating[Date] = CurrentDate
),
MAX ( Rating[Rating Value] )
)