Difference between two sigmoidal functions membership function
y = dsigmf(x,[a1 c1 a2 c2])
The sigmoidal membership function used depends on the two parameters a and c and is given by
The membership function dsigmf depends on four parameters, a1, c1, a2, and c2, and is the difference between two of these sigmoidal functions.
f1(x; a1, c1) - f2(x; a2, c2)
The parameters are listed in the order: [a1 c1 a2 c2].