lib/root.c


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// Nth Root
//
// n_root - nrt
//
// f( x ) = x^( 1 / n )
//
// X_n - 1
// Y_n - 1
// C_n - 1
//
// c[0] = n


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


typedef struct {
    fp_t r;
} ts_root_params_t;

ts_parameter_t const ts_root_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 1, .params_size = sizeof(ts_root_params_t) };


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

int ts_root(
	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_root_p );
	if ( !c ) return -1;
	fp_t r = ((ts_root_params_t const *)c)->r;
	if (r == 0) return -1;

	for( uint_t i = 0; i < n; ++i )
	{
		y[0][i] = pow( x[0][i], _ts_reciprocal( r ) );
	}
	return 0;
}