Forum Discussion
Unexpected Result With Matrix Conditional Formatting
Hi AUaero ,
According to the reply from the product group, Power BI implements the color gradient as a linear scale. You can set the Middle to a different value if you want, but by default Middle is the average of min/max.
They will take the idea from you into consideration for adding more Auto options to "middle".
Best Regards
Community Support Team _ Polly
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
I would expect the middle value to the median, but I haven't found any documentation regarding conditional formatting that explains exactly what Power BI treats as the middle value. Regardless, the value that is highlighted as the middle is neither the mean nor the median.
I can't share the full PBIX but I've created a stripped down version that replicates the problem. As you can see, Power BI is treating the middle value as 103,391 while the median is 88,794 and the average is 92,752.
I can't share the the full PBIX due to confidentiality concerns, but here's a link to a simplified and sanitized version.
Yeah, it's a bit off. Dashed is median, solid is mean/average. Middle color is supposed to be white which is kinda absent.
You can raise an issue at https://issues.powerbi.com . If you have a Pro license you can consider raising a Pro ticket at https://powerbi.microsoft.com/en-us/support/pro/
It appears to be taking the max value of the list and subtracting the min value of the list. That number divided by two and then added to the min value to get the "middle value".
nice theory but doesn't seem to hold
middle measure = var a = summarize('IAM Performance','IAM Performance'[IAMName],"s",[$ Sales / Day]) return 0.5*(maxx(a,[s])+minx(a,[s]))/17Edit: never mind, didn't see the calendar filter.
Note: (MIN+MAX)/2 is faster.
I think you're onto something here. Using your algorithm, I come up with 106,214 as the "middle" value. This jives with with what Power BI is actually highlighting as the middle value.
Did you find this in the documentation somewhere or just figure it out? Regardless, this seems like a dumb way to find the "middle". This approach gives you average of the min and max values. The middle of a set of numbers is the median.
Thanks for validating the problem - I suspected that this was a bug in the conditional formatting. I've submitted an issue.
Here's a link to the issue I've submitted. Based on jgeddes findings I guess this isn't necessarily a bug, just a dumb way of resolving the middle value. Please take a minute to go vote on this idea if you think the middle value should be the median instead of the average of the min and max values.
Gradient conditional formatting doesn't accurately... - Microsoft Power BI Community
A compromise would be to allow the developer to specify the rule that decides the "middle" color.
Worst case you would have to roll your own coloring rules.
