I'm having difficulty displaying the plot that I want, and I believe part of it might come from a misunderstanding of how the timeavg() operator works. I simulated a time-dependent PDE on the surface of a sphere for 1000 seconds, saving the output every 10 seconds. At every time, the variable, u, is roughly between the values of 19 and 20. I now plot the expression
timeavg(100, 1000, u)
To my confusion, the resulting plot shows the value ranging between -10 and 40. I can even output the time evolution as a video, and see that the original variable u fluctuates between 19 and 20 on the sphere, but the "time average" somehow ends up having a much wider range. Am I misunderstanding how the operator should work?
I would attach the file in question, but the simulation is rather time-intensive, and hopefully this problem is just a simple matter of confusion on my part.