Information Technology Reference
In-Depth Information
Fig. 5.14
An exponential sigmoid function
Fig. 5.15
A Hill function where
A
=
10,
B
=
5,
n
=
4
f
(
x
)=
ax
(
1
−
x
)
.
This form expresses the size at the next step, as depending at the same time on the
number of living individuals
x
and on the number of potential living individuals
which can be added for reaching the maximum size. The parameter
a
is specific of
any particular kind of logistic rule. If we want to move from the function
f
to the
time series
G
f
(
n
)
, along the generation steps, we need to consider the iteration of
f
, therefore:
f
n
x
0
)
where
x
0
is the size of the population at the initial time.
G
f
(
n
)=
(
