Count rows with multiple conditions

[powerbiuser12]

I would love to get some help in counting how many of the 'courses that count for credit' a 'person' has taken, i.e.; if you take a 'courses that counts for credit' twice you only recieve credit for one.  Right now all I have is the Person/Course Table.  My expected results are shown in the last table below.  e.g.; Eventhough Squares is a course that counts for credit, Bill only gets one credit when he actually took Squares twice. 

Person	Course
Bill	Squares
Bill	Squares
Bill	Triangles
Bob	Circles
Bob	Rectangles
Lisa	Squares
Lisa	Triangles
Lisa	Rectangles
Lisa	Rectangles
Jennifer	Ovals
Tom	Polygons
David	Ovals
David	Squares
Daniel	Squares

Courses that count for credit

Squares

Rectangles

Ovals

	Expected Output
Bill	1
Bob	1
Lisa	2
Jennifer	1
Tom	0
David	2
Daniel	1

[powerbiuser12]

Thanks for the super fast response @jdbuchanan71 !  It worked.  Hopefully I put this issue in generic enough terms others will gain value from it too.

I was trying to think of a way to do it using IF, Countrows, Distinct, and Filter but couldn't put all the pieces together.  Your solution is simple and elegant but seemingly a little more advanced to a new user like myself by creating variables.  Is there a "messier" version using more off-the-shelf functions in DAX perhaps that I should have been able to piece together?

Again thanks for the help.

[powerbiuser12]

One other solution I tried was to display the data in a Matrix with the Courses in the Rows and the Names in the Columns then apply a Visual level filter and select only the "Courses that counted for credit".  The downside is I have about 500+ names and the Matrix stops at about letter C in my alphabetical names list so I applied a data slicer to let the report user hone in on a name or set of names but the solved solution does what I was after better.

[jdbuchanan71 · Accepted solution]

Hello @powerbiuser12 

You can use something like this.

Counted Courses = 
VAR Countedcourses = {"Squares", "Rectangles", "Ovals"}
VAR TheCount = 
    CALCULATE (
        DISTINCTCOUNT ( YourTable[Course] ),
        YourTable[Course] IN ( Countedcourses )
    )
RETURN
    IF ( ISBLANK ( TheCount ), 0, TheCount )