|Metrix » Tuning|
When you select to tune with no variables or weather, the constant you see in the tuning form is the average of the kWh/day for all the months during the tuning period. The average kWh/day is taken for each billing period, and then averaged. If all you wanted to do is to get the average kWh per day, indeed it would be better to take the ratio of total kWh to total days elapsed, instead of taking the average of the ratios computed for each bill, as we do now.
In regressions, for each billing period, Metrix finds the average kWh/day, where (for reasons explained in our documentation and in a white paper) we regress kWh/day vs. CDDs/day, widgets/day, etc.
Because we didn't believe that tuning using the average kWh/day was very useful, we didn't create a separate calculation routine for the limiting case of 0 variables. The fact that you could choose it was done simply for consistency. Now that you call this to our attention, we can think of some potential problems if a user uses "no variables" and no bill matching modification.
If you want to tune using the average kWh/day, then compute the right ratio manually (using annual total kWh and annual total days from contract report) and enter it in the constant, after switching the tuning screen to manual.
Otherwise feel free to contact our Tech Support staff at (805) 329-6565, or via email at firstname.lastname@example.org.