Y = VL_SIGMOID(X) returns
Y = 1 ./ (1 + EXP(X)) ;
- Remark
Useful properties of the sigmoid function are:
1 - VL_SIGMOID(X) = VL_SIGMOID(-X)
Centered sigmoid: 2 * VL_SIGMOID(X) - 1 ;
VL_SIGMOID(X) = (EXP(X/2) - EXP(X/2)) / (EXP(X/2) + EXP(X/2))
See also: VL_DSIGMOID(), VL_HELP().