Can you see a difference between analyzing based on measurement and analyzing based on knowing the actual underlying function? Walter, I don't. Since we don't have a closed form "actual function" in casting I don't see how you could make that distinction in the way we compute velocity (or...

If I start with a known function I can make it as accurate as I want. Walter, How about an example to illustrate what you are saying? and I don’t know the underlying function then I’m basically doing a statistical analysis. I thought you would be a numerical derivative of the data points rather tha...

I just chuck the Runge-Kutta at everything these days because I've forgotten how to do maths James, I am always looking for better numerical differentiation routines. Is there a Runge-Kutta approach for doing numerical differentiation, or does that powerful technique just apply to doing the numeric...

Another area I think would be of value is to look at active hauling vs passive hauling. Walter, The haul hand path that we can produce with the back cast haul tends to take advantage of of the "passive" haul speed that is associated with the rotation of the stripper guide. I do think that...

We can reduce the amount of error by improving measurement accuracy and averaging over several datasets but it's still a statistical issue. Walter, Can you give an example of taking the numerical derivative of a known function (sin(x)) for example and compare its results with the close form value? ...

I can measure this distance fairly easily using video. Walter, "fairly easily" may be a simplification when the line has a curved path as shown in this frame grab of Lasse's video with the line marker. How would you recommend that the arc distance in the line between the rod tip and line ...

My suggestion is that we define haul as relative movement between the line and rod hands during the casting stroke. Walter, Your forgetting that the haul distance is the difference between the haul hand and the stripper guide not the distance between the hands. Your definition would leave out the i...

but to say you’ve taken the derivative instead of numerical differentiation implies a different process and a potentially different result. Walter, "Potentially different" seems to be the operative word in that assessment. There are dozens of numerical derivative algorithms for calculatin...

It may seem pedantic

Walter,
I agree.
Gordy

in order to determine a derivative you would need to know the function you are deriving it from. Walter, I agree. The function is the distance between the stripper guide and the haul hand as a function of time. As explained that difference is obtained using a variable reference frame in Tracker. Tr...