Math Vector Library 1.1 Machine Learning Extension
Programming Reference Manual C/C++
Version 1.1 DD-00004-011

4.32 vmlelud - ELU activation (first derivative)

#include <mvecml.h> 
 
void vmlelud(int n, double *restrict y, int incy, 
             double a, const double *restrict x, int incx); 
void vmleludf(int n, float *restrict y, int incy, 
              float a, const float *restrict x, int incx); 
 
 
#include <mvecml64.h> 
 
void vmlelud_64(long n, double *restrict y, long incy, 
                double a, const double *restrict x, long incx); 
void vmleludf_64(long n, float *restrict y, long incy, 
                 float a, const float *restrict x, long incx);

Given an input vector x, a result vector y and constants λ and α this function computes the first derivative of the Exponential Linear Unit (ELU) activation function of the values in the x vector and stores the result in the y vector.

  .{ 1       wherex >0
y =
     αexp(x)  wherex ≤0
4.32.1 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: incy̸= 0.
BEHAVIOR: A negative stride will traverse the array in reverse.

A - REAL

ENTRY: Constant a .

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: incx̸= 0.
BEHAVIOR: A negative stride will traverse the array in reverse.