Figure 1: Time-Dependence of a Continuous Logistic-Function and its Derivatives. Values of the logistic function (Y) and the first five of its derivatives with respect to time (Y’, Y’’, Y’’’, Y’’’’, Y’’’’’) are on the ordinates. Time is denoted on the abscissas. The function (Y) is given in equation 1. Parameter (a) was varied from 0.0 to 2.0 in increments of 0.1. Time derivatives of equation 1 were obtained with Maple 15.01 (Maplesoft, a division of Waterloo Maple, Inc.). Graphs were plotted with Python 2.7.3 {EPD 7.3-1 (64-bit)}, SciPy and matplotlib.