Order changes, updated ToDo

ToDo.txt

@@ -0,0 +1,8 @@
+(1) Make the "time_average" fully depend on the "time_integrals" output
+    - We can change the "TimeSeries" output one element at a time (dividing by dt) in order to minimize allocations
+
+(2) Make the "time_integrals" less dependent on the total cumulative integral
+    - Reconstruct local cumulative integrals to interpolate
+        - Use the existing time_integral(ts::AbstractTimeSeries{T}, Δt::TimeInterval) implementation which is efficient
+        - Consider adding an "indhint" argument to make it more efficient (with an indhint output)
+    - Modify the interpolated results by subtracting the first value

src/time_integral.jl

@@ -6,7 +6,7 @@ Time-weigted averages between the nodes of vt using either
 Timestamps in the resulting period refers to the END of the integral period, so the first element is always NaN
 """
 function time_averages(ts::AbstractTimeSeries{T}, vt::AbstractVector{<:Real}; order=1) where T
-    ∫ts = interpolate(cumulative_integral(ts, order=order), vt, order=order)
+    ∫ts = interpolate(cumulative_integral(ts, order=order), vt, order=1)
     return TimeSeries(vt, [NaN; diff(values(∫ts))./diff(vt)])
 end