HFpostdoc / unstable_states

What do dynamics look like in systems without stable states?
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What initial value of r should you use? #3

Closed MKLau closed 10 years ago

MKLau commented 10 years ago

Simulating population dynamics for the logistic difference equation where the "biotic potential" parameter, r, is altered.

MKLau commented 10 years ago

spark_r

MKLau commented 10 years ago

The value of the chaotic boundary is exactly 3.570.

In this simulation, the number of basins (i.e., attractors of x when rounded to 4 decimals) was counted for values of r from 1 to 4 at the hundredths place starting from an initial value of x = 0.1.

In order to control for the transience period, the initial 2000 values were removed.

At r = 3.570, the number of basins immediately exceeds 100.

screen shot 2014-05-22 at 6 09 45 pm

MKLau commented 10 years ago

There is another area of chaotic behavior around 3, but tuning is very fine within this region.

screen shot 2014-05-22 at 6 23 31 pm

MKLau commented 10 years ago

Using a threshold of 3.57, which is what was also initially stated by May 1976.

MKLau commented 10 years ago

Here is a better figure that shows more useful regions with moderate numbers of attractors.

screen shot 2014-05-22 at 6 48 21 pm

MKLau commented 10 years ago

Move a fixed distance across each threshold of attractor number as determined by the maximum distance possible from the 4th attractor set into chaos.