Math Vector Library Machine Learning Extension
Programming Reference Manual
Version 1.0 DD-00004-110

4.16 vmlssgnd - Softsign activation (first derivative)

subroutine vmlssgnd (n, y, incy, x, incx);
subroutine vmlssgndf(n, y, incy, x, incx);

Given an input vector x  and a result vector y  this function computes the first derivative of the Softsign activation function of the values in the x  vector and stores the result in the y  vector.

y .=-2---|x-|---2-
   (x  +1)|x|+2x

4.16.1 Parameters

N - INTEGER

ENTRY: Number of elements of x  and y  .
CONSTRAINT: n ≥1  .

Y - ARRAY OF REAL

EXIT: Result vector y  .
CONSTRAINT: Must contain n× incy  elements.
CONSTRAINT: Must not overlap with array x  .

INCY - INTEGER

ENTRY: Stride for the vector y  .
CONSTRAINT: incy> 0  .

X - ARRAY OF REAL

ENTRY: Input vector x  .
CONSTRAINT: Must contain n× incx  elements.
CONSTRAINT: Must not overlap with array y  .

INCX - INTEGER

ENTRY: Stride for the vector x  .
CONSTRAINT: incx> 0  .