Double Logistic Function
The double logistic is a function similar to the logistic function with numerous applications. Its general formula is:
where d is its centre and s is the steepness factor. Here "sgn" represents the sign function.
It is based on the Gaussian curve and graphically it is similar to two identical logistic sigmoids bonded together at the point x = d.
One of its applications is non-linear normalization of a sample, as it has the property of eliminating outliers.
Read more about this topic: Logistic Function
Famous quotes containing the words double and/or function:
“I grew up confidently expecting to have a profession and earn my own living, and also confidently expecting to be married and have children. It was fifty-fifty with me. I was just as passionately determined to have children as I was to have a career. And my mother was the triumphant answer to all doubts as to the success of this double role. From my earliest memory she had more than half supported the family and yet she was supremely a mother.”
—Crystal Eastman (1881–1928)
“The fact remains that the human being in early childhood learns to consider one or the other aspect of bodily function as evil, shameful, or unsafe. There is not a culture which does not use a combination of these devils to develop, by way of counterpoint, its own style of faith, pride, certainty, and initiative.”
—Erik H. Erikson (1904–1994)