# Interpolation with conditional pricing

I have 6 attributes: A, B, C, D, Speed, Price.

Speed and price are continuous; conditional pricing is as follows:
Speed =  100, Price = 2, 3, 4
Speed = 400, Price = 4, 6, 8
Speed = 4000, Price = 10, 15, 20

I'm interested in simulations where Speed = 2000 and prices are varied in the range of 10 to 20. However, when I set Speed = 2000, the simulator assumes that Prices 4, 6, 8 are applicable. I'm guessing it views the Speed levels as thresholds for which price sets apply.

When I set Price to a value such as 12, the simulator thinks I'm requesting an "extrapolation." One consequence of this is that it prevents using RFC. I'm able to use Share of Preference with a Price such as 12 but it must be interpolating Speed (since 100  < 2000 < 4000) while extrapolating Price (since 4 < 6 < 8 < 12).

However, in my real-world context, it is more reasonable to assume Prices are in the range of 10 to 20 rather than 4 to 8 when Speed = 2000. Is there a way to configure the simulator to associate the highest price set (10, 15, 20) when Speed = 2000 ?

I've tried hand-calculations on the Excel simulator utilities to replicate the dual interpolation/extrapolation that Share of Preference is performing. I doubt I'll figure out how to extend to RFC. Thus, I was hoping there is a way to change which (conditional) price range the simulator is associating with my interpolated Speed.
Are the issues occurring in the Choice Simulator or in an Excel simulator you've exported? Conditional pricing is not exported to the Excel simulator, and you'll need to create your own interface to translate the conditional table values.
The issue is in the choice simulator. I only went to the Excel simulator to test some ideas about how the choice simulator was operating. I assume the choice simulator is behaving as intended since it seems reasonable to apply a lower price set until the conditioning attribute reaches its next designed level. IN my example, the choice simulator "pre-populates" the middle price set (4, 6, 8) when I enter a Speed value of 2000, which sits above its middle design value (400) but below its highest design value (4000). However, in my context, I'd like the simulator to pre-populate the highest price set (10, 15, 20) so that I would be interpolating prices within that range (e.g., price = 12) rather than extrapolating upward from the middle price set (4, 6, 8).
I just noticed that you're trying to interpolate on Speed, one of the conditional attributes. The simulator can't deal with that situation, because it can't match prices your typed in to a value in the table.

One way to accomplish it would be to disable the conditional price table and use price values on the 1,2,3 scale.