blob: e77d8b067d22463577a5df60b54fac0b1462e8d1 (
plain)
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
52
53
54
55
56
57
58
59
60
61
62
63
64
|
// Dawson Integral
//
// dawsn - Dawson function
//
// F(x) = e^(-x²) * ∫₀ˣ e^(t²) dt
//
// Inputs: 1
// Outputs: 1
// Constants: 0
#include <math.h>
#include "ts.h"
ts_parameter_t const ts_dawsn_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };
uint_t ts_dawsn_offset( ts_constant_t const *c )
{
( void )c;
return ( 0 );
}
int ts_dawsn(
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_dawsn_p );
(void)c;
for( uint_t i = 0; i < n; ++i )
{
fp_t val = x[0][i];
fp_t ax = fabs( val );
fp_t y_val;
if( ax < 3.0 )
{
fp_t t = ax;
fp_t s = t;
for( uint_t k = 1; k < 20; ++k )
{
t *= -2.0 * ax * ax / (fp_t)(2 * k + 1);
s += t;
}
y_val = s;
}
else
{
y_val = 1.0 / ( 2.0 * ax + 1.0 / ( 2.0 * ax + 3.0 / ( 2.0 * ax + 5.0 / ( 2.0 * ax ) ) ) );
}
if( val < 0 )
y_val = -y_val;
y[0][i] = y_val;
}
return 0;
}
|