lib/expit.c


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// Inverse Logit (Expit)
//
// expit - logistic function
//
// y = 1 / (1 + e^(-x))
//
// Inputs:    1
// Outputs:   1
// Constants: 0

#include <math.h>
#include "ts.h"


ts_parameter_t const ts_expit_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };


uint_t ts_expit_offset( ts_constant_t const *c )
{
	( void )c;
	return ( 0 );
}

int ts_expit(
	fp_t * const *y, uint_t y_n,
	fp_t const * const *x, uint_t x_n,
	uint_t n, ts_constant_t const *c
)
{
	TS_PROLOGUE( ts_expit_p );
	(void)c;
	for( uint_t i = 0; i < n; ++i )
	{
		y[0][i] = 1.0 / ( 1.0 + exp( -x[0][i] ) );
	}
	return 0;
}