// Performance Ratio
//
// performance_ratio
//
// Performance Ratio
//
// 
//
// Inputs:    1
// Outputs:   1
// Constants: 1


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

typedef struct {
    uint_t k;
} ts_performance_ratio_params_t;

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

uint_t ts_performance_ratio_offset( ts_constant_t const *c )
{
	( void )c;
	return ( c ? ((ts_performance_ratio_params_t const *)c)->k : 0 );
}

int ts_performance_ratio(
	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_performance_ratio_p );
	if ( !c ) return -1;
    uint_t k = ((ts_performance_ratio_params_t const *)c)->k;
    if (k <= 1) return -1;

    fp_t factor = (fp_t)k / (k - 1);

    for( uint_t i = k; i < n; ++i )
    {
        fp_t v = x[0][i - k + 1];
        fp_t inner = v * v - 1;
        y[0][i] = inner >= 0 ? sqrt( factor * inner ) : 0;
    }
	return 0;
}