The Crazy Zoo That Dudley Drew

Back from a week in Virginia beach. Had a great time, discounting the smoke from the Dismal Swamp.

I proved to myself that the calculations of the model were repeatable, so I don't have a random source of error.

I started to dump the position and velocity of every segment of the ribbon at the end of the simulation. I changed the output format so I could copy them from the console to a text file, and then import the data into Excel, where I can chart the data to my heart's content.

Something mysterious is happening to the segment velocities at the base of the ribbon when I go from four hundred eighty-five segments to four hundred and ninety segments.

I'll need to verify that all of the equations that transform forces into velocities, and velocities into changes in position, have the correct time delta applied. I also need to look for discontinuities in how I am handling the boundary conditions near the base of the ribbon (for both the anchor point, and the surface of the Earth check).

One of my thoughts is that between changing the position of a ribbon segment and checking for whether the segment position is below the Earth's surface, that there is a calculation of ribbon forces based position and velocities of adjoining segments. I may try to do the surface check immediately after recalculating position, to eliminate a source of error.

I plan to re-run the model to collect the intermediate data to try and pinpoint when the error starts to occur, to see if that provides additional insight into why the model is acting up.