Front Office Football Central - View Single Post - Yet another person learning Python

nilodor · 09-19-2016, 10:51 AM

So we need a mule to carry us through our data set analyses and what better mule than old glue factory himself, Usain Bolt.

Here are his splits from the Berlin World Championship

Code:

Distance	Time (sec.)	Split (sec.)
Reaction time	0.146 s	
10m	       1.85 s  	1.704 s
20m	       2.89 s	        1.04 s
30m	       3.78 s	        0.89 s
40m	 	4.64 s	0.86 s
50m		 5.49 s	0.85 s
60m		 6.31 s	0.82 s
70m		 7.11 s	0.80 s
80m	 	7.92 s	0.81 s
90m	 	8.74 s	0.82 s
100m		  9.58 s	0.84 s

What I'd like to find is a function that fits the data, and also has some physical meaning (i.e. I can turn the constants into ratings).

After a few tries I settled upon using two functions for position as a function of time. A power law A*t^B for the first portion of the race and a good ol linear function for part two of the race. My switch is when the velocities are equal I'll move from the power law to the linear function.

The nice things are, for the linear function the constant is the sprinters maximum velocity. Also, both functions are relatively easy to take derivatives of so I can find the velocity and acceleration at any time.

While linear may not be the best fit ever, I think it's a reasonable compromise for now. I'll look at updating this after I've come up with some equations for the 200 m race.

Next up it's time to look at what range of coefficients I should use.

09-19-2016, 10:51 AM	#12
nilodor College Benchwarmer Join Date: Oct 2000 Location: calgary, AB	So we need a mule to carry us through our data set analyses and what better mule than old glue factory himself, Usain Bolt. Here are his splits from the Berlin World Championship Code: Distance Time (sec.) Split (sec.) Reaction time 0.146 s 10m 1.85 s 1.704 s 20m 2.89 s 1.04 s 30m 3.78 s 0.89 s 40m 4.64 s 0.86 s 50m 5.49 s 0.85 s 60m 6.31 s 0.82 s 70m 7.11 s 0.80 s 80m 7.92 s 0.81 s 90m 8.74 s 0.82 s 100m 9.58 s 0.84 s What I'd like to find is a function that fits the data, and also has some physical meaning (i.e. I can turn the constants into ratings). After a few tries I settled upon using two functions for position as a function of time. A power law A*t^B for the first portion of the race and a good ol linear function for part two of the race. My switch is when the velocities are equal I'll move from the power law to the linear function. The nice things are, for the linear function the constant is the sprinters maximum velocity. Also, both functions are relatively easy to take derivatives of so I can find the velocity and acceleration at any time. While linear may not be the best fit ever, I think it's a reasonable compromise for now. I'll look at updating this after I've come up with some equations for the 200 m race. Next up it's time to look at what range of coefficients I should use.