Help with Complex Line Chart

[#1]

Hi,

I need to create a line chart that represents Change in Unit Sales by Vendor

x-Axis --> Rolling 5 quarters (QTD + previous 4 Quarters)

y-Axis --> %Change = (CurrentQtr / LastYrQtr) - 1

Chart lines --> one for each Vendor

I was able to use set analysis in expressions to get a chart straight table of this working, as follows:

Dimensions: Vendor

Expressions: each of the 5 quarters represented as a different expression. For example:

(sum({<YearQtr={"$(vCurrentYearQtr)"}>} POSQty) / sum({<YearQtr={"$(vLastYearQtr)"}>} POSQty))-1

Here's an example of the result:

However, when I attempt to convert to a line chart, I receive an error 'No numeric values on x-axis'

Does anyone have an idea on how to create this chart?

Here's an example of my fact table:

WeeklyData

Vendor

WeekEndDate

Year

Quarter

YearQtr

POSQty

Where there is one line for each WeekEndDate of each year.