What Is Fuzzy Logic?

dsigmf
Purpose
Syntax
Description
Built-in membership function composed of difference between two
sigmoidal membership functions
y = dsigmf(x,[a1 c1 a2 c2])
The sigmoidal membership function used depends on the two
parameters a and c and is given by
( ) =
+
− −
f x; a,
c
1
1
e ax ( c )
The membership function dsigmf depends on four parameters, a1,
c1, a2, andc2, and is the difference between two of these sigmoidal
functions.
f 1
(x; a 1
, c 1
)-f 2
(x; a 2
, c 2
)
The parameters are listed in the order: [a 1
c 1
a 2
c 2
].
Examples
x=0:0.1:10;
y=dsigmf(x,[5 2 5 7]);
plot(x,y)
xlabel('dsigmf, P=[5 2 5 7]')
1
0.75
0.5
0.25
0
0 2 4 6 8 10
dsigmf, P = [5 2 5 7]
4-13