lib/pivot_points.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51

// Pivot Points
//
// pivot_points
//
// Pivot Points
//
// 
//
// Inputs:    5
// Outputs:   5
// Constants: 0


#include "ts.h"


ts_parameter_t const ts_pivot_points_p = { .n_inputs = 4, .n_outputs = 5, .n_constants = 0, .params_size = 0 };

uint_t ts_pivot_points_offset( ts_constant_t const *c )
{
	( void )c;
	return ( 1 );
}

int ts_pivot_points(
	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_pivot_points_p );
	(void)c;
    if (n > 0) { y[0][0] = 0; y[1][0] = 0; y[2][0] = 0; y[3][0] = 0; y[4][0] = 0; }
    for( uint_t i = 1; i < n; ++i )
    {
        fp_t prev_h = ts_h( x, i - 1 );
        fp_t prev_l = ts_l( x, i - 1 );
        fp_t prev_c = ts_c( x, i - 1 );

        fp_t p = ( prev_h + prev_l + prev_c ) / 3.0;
        fp_t range = prev_h - prev_l;

        y[0][i] = p;
        y[1][i] = 2.0 * p - prev_l;
        y[2][i] = 2.0 * p - prev_h;
        y[3][i] = p + range;
        y[4][i] = p - range;
    }
	return 0;
}