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All Topics | Topic "Potential Issue with XA Solver/WEAP 2019.2"
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Author Message
Mr. James Syme

Subject: Potential Issue with XA Solver/WEAP 2019.2   
Posted: 8/20/2019 Viewed: 7408 times
I'm working with a model that is showing very unusual results for reservoir outflows under the XA solver. I have an "Other" expression that includes a call to PrevTSValue(...RES:Total Node Outflow[m^3]). This Other expression shows a value of 50,000,000,000 for one month during the runs (and has previously shown other enormous values—e.g., > 5*10^9—for a few months).

There are two issues—first, there isn't that much water in the system that we're modeling. Second, when I look through the favorites to look at the total reservoir outflow, there's nothing of that scale shown; the value is 0. Do you know what might be causing this? Could this be some kind of flag in the XA Solver output?

I'll note that, before updating to 2019.2, we had not run into this issue. It started right after the update to 2019.2.

I've tried the following remedies:

- Deleting and re-implementing the reservoir
- Setting capacity to 0.0 during the time period where the large number is showing up

Update: I wanted to add that I tried with this LP Solver, and it still gives me odd numbers. It appears as though the model is showing inflows/outflows from a reservoir when I use the PrevTSValue call in an "Other Assumption" variable, but I don't see those inflows/outflows in the favorites at all.



Mr. Jack Sieber

Subject: Re: Potential Issue with XA Solver/WEAP 2019.2   
Posted: 9/10/2019 Viewed: 7400 times

That is strange indeed. If it happens with both the XA and lpsolve solvers, sounds like the problem is not with the solver.

Can you please send me your WEAP area so that I can test it? The easiest way to do this is from WEAP. On the main menu, go to Help, Send Email to WEAP Support. Make sure to select "Attach area" so that WEAP will attach your area to the email to me.

Best regards,

Topic "Potential Issue with XA Solver/WEAP 2019.2"