Sigmoid Curve Erf

[My Gallery of Graphs] Mastering the art of building classic and stylish graphics in R: Sigmoid Erf

1. −1.0 −0.5 0.0 0.5 1.0
−1.0
−0.5
0.0
0.5
1.0
x
y
=
f
(
x
)
-0.75 -0.25 0.25 0.75
l l l
l
l
l
l
l
l
(−1,0) (0,0) (1,0)
(1,1)
(−1,−1)
(−1,1)
(1,−1)
(0,1)
(0,−1)
l
curve:  erf
some notable points
area under the curve