I want to divide a sigmoid function to three functions, I found this function:
Where The five parameters in this model have the following meaning: alpha is the initial size of y, beta represents the intrinsic growth rate of the exponential phase, t1 is the transition point between the first two phases, epsilon is the length of the linear phase, and gamma is the intrinsic saturation rate.
I set t1=5, t2=10, lamda=0.1, B=1 to plot a shape like the shape showed in the picture 2. but I have not a positive results. any helps ?