diff options
| author | Ethan Werner <mail@ethanwerner.com> | 2026-07-01 09:42:39 +0400 |
|---|---|---|
| committer | Ethan Werner <mail@ethanwerner.com> | 2026-07-01 09:42:39 +0400 |
| commit | 07e18043145f3d91c8ea7ec3ad41b3c905585277 (patch) | |
| tree | 2bdeae46973f4bdfce263679a4008ac768011f28 /lib/prime_number_bands.c | |
initial commit: ts time series analysis library v0.1.0
- 354 financial and mathematical time-series indicators
- Uniform C11 API with consistent function signatures
- 349 passing tests with -Werror
- Static and shared library builds
- pkg-config integration
- Python bindings
- Fuzzing and sanitizer support
- Security hardening flags
Diffstat (limited to 'lib/prime_number_bands.c')
| -rw-r--r-- | lib/prime_number_bands.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/lib/prime_number_bands.c b/lib/prime_number_bands.c new file mode 100644 index 0000000..ac94e7b --- /dev/null +++ b/lib/prime_number_bands.c @@ -0,0 +1,58 @@ +// Prime Number Bands +// +// prime_number_bands +// +// Prime Number Bands +// +// +// +// Inputs: 1 +// Outputs: 3 +// Constants: 1 + + +#include <math.h> +#include "ts.h" + +typedef struct { + uint_t k; +} ts_prime_number_bands_params_t; + +ts_parameter_t const ts_prime_number_bands_p = { .n_inputs = 1, .n_outputs = 3, .n_constants = 1, .params_size = sizeof(ts_prime_number_bands_params_t) }; + +uint_t ts_prime_number_bands_offset( ts_constant_t const *c ) +{ + ( void )c; + return ( c ? ((ts_prime_number_bands_params_t *)c)->k - 1 : 0 ); +} + +int ts_prime_number_bands( + 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_prime_number_bands_p ); + if ( !c ) return -1; + uint_t k = ((ts_prime_number_bands_params_t *)c)->k; + if (k == 0 || n < k) return -1; + + for( uint_t i = k - 1; i < n; ++i ) + { + fp_t sum = 0, sum2 = 0; + for( uint_t j = 0; j < k; ++j ) + { + fp_t v = x[0][i - k + 1 + j]; + sum += v; + sum2 += v * v; + } + fp_t mean = sum / k; + fp_t variance = sum2 / k - mean * mean; + fp_t stddev = variance >= 0 ? sqrt( variance ) : 0; + y[0][i] = mean; + y[1][i] = mean + 2.0 * stddev; + y[2][i] = mean - 2.0 * stddev; + } + return 0; +} + |