Logistic sigmoid (Geron Ch 4, morie.fn hmsigm)

Overflow-safe two-branch evaluation, with the elementwise derivative a (1 - a). The slope peaks at 0.25.

Usage

morie_geron_sigmoid(t)

Arguments

t

Numeric vector.

Value

List with a, sigma, grad, estimate, n.

Examples

V <- c(1, 2, 3, 4, 5, 6, 7, 8)
morie_geron_sigmoid(V)
#> $a
#> [1] 0.7310586 0.8807971 0.9525741 0.9820138 0.9933071 0.9975274 0.9990889
#> [8] 0.9996646
#> 
#> $sigma
#> [1] 0.7310586 0.8807971 0.9525741 0.9820138 0.9933071 0.9975274 0.9990889
#> [8] 0.9996646
#> 
#> $grad
#> [1] 0.1966119332 0.1049935854 0.0451766597 0.0176627062 0.0066480567
#> [6] 0.0024665093 0.0009102212 0.0003352377
#> 
#> $estimate
#> [1] 0.942004
#> 
#> $n
#> [1] 8
#> 
#> $method
#> [1] "Logistic sigmoid, overflow-safe branch, with elementwise derivative"
#>