•install.packages("pracma")
•library(pracma)
•x <- seq(-6, 6, length.out = 101)
## sigmoid(x, a = 1, b = 0). y = 1/(1 + e^{-a (x-b)})
•y1 <- sigmoid(x)
•y2 <- sigmoid(x, a = 2)
## Not run:
•plot(x, y1, type = "l", col = "darkblue",
xlab = "", ylab = "", main = "Sigmoid Function(s)")
•lines(x, y2, col = "darkgreen")
•grid()