How to extend/append values to a X/Y line chart dataset

I am working on creating a simple X/Y line chart that presents X values as dates and Y as sales ($) volume. I would like to extend that with a simple regression routine and populate the projections out 90/120 days. I have managed to get a JavaScript function to calculate the values for Y given the future X, but charting those values is turning out to thwart me. Anyone have examples on how to append new values to the X series data? If I/we owned the app, I could easily drop in a stored proc that would generate the future dates and union those w/ my query. Alas, the app owners are less than excited about that.

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micajblock

Why not add another data set?

johnsonj

I could not find any examples of simply, "adding" another dataset to the X series data (hints would be greatly appreciated). Since the values I need to append to the X series data are calculated in Javascript, I do not have the ability to bring in the data via an easily select statement. Can anyone point me to an example of "Merging" two datasets? Maybe that would be a place to start.

micajblock

Here is what I would do.1. Create a scripted data set with projected data.2. Create a joined data set between the real data and the scripted data (use full outer join).3. Create computed columns that will alternate between the real data and the projected data4. Build the chart off the joined data set. If you are using commercial BIRT you can replace steps 2 and 3 with a Union data set. P.S. What version of BIRT are you using?