Fix correlation coefficient Quick Measure

Power BI includes a quick measure for calculating the correlation coefficient between 2 sets of data in a scatterplot. However the calculation does not seem to filter out (X,Y) pairs where one of the data points is missing. I just looked into some wrong numbers appearing in my report (a positive waek correlation that gave a negative value for R, the Pearson Correlation Coefficient).

This blog post has more on the topic.

https://xxlbi.com/blog/pearson-correlation-coefficient-in-dax/