lib/harmonic.c


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// Harmonic
//
// harmonic
//
// Harmonic mean
//
// H = n / Σ(1/x_i)
//
// Inputs:    1
// Outputs:   1
// Constants: 0


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


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

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

int ts_harmonic(
	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_harmonic_p );
	(void)c;
    for( uint_t i = 0; i < n; ++i )
    {
        if (x[0][i] < 0) { y[0][i] = NAN; continue; }
        uint_t n_val = (uint_t)x[0][i];
        if (n_val > 10000000) n_val = 10000000;
        fp_t sum = 0.0;
        for( uint_t k = 1; k <= n_val; ++k )
        {
            sum += 1.0 / (fp_t)k;
        }
        y[0][i] = sum;
    }
	return 0;
}