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| 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/factorial.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/factorial.c')
| -rw-r--r-- | lib/factorial.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/lib/factorial.c b/lib/factorial.c new file mode 100644 index 0000000..8e64fa3 --- /dev/null +++ b/lib/factorial.c @@ -0,0 +1,47 @@ +// Factorial +// +// factorial - n! +// +// n! = 1 * 2 * ... * n, capped at 170! +// +// Inputs: 1 (n) +// Outputs: 1 (n!) +// Constants: 0 + +#include "ts.h" + + + +ts_parameter_t const ts_factorial_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 }; + + +uint_t ts_factorial_offset( ts_constant_t const *c ) +{ + ( void )c; + return ( 0 ); +} + +int ts_factorial( + 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_factorial_p ); + (void)c; + for( uint_t i = 0; i < n; ++i ) + { + if (x[0][i] < 0) { y[0][i] = NAN; continue; } + fp_t result = 1.0; + uint_t k = (uint_t)x[0][i]; + if (k > 170) k = 170; + for( uint_t j = 1; j <= k; ++j ) + { + result *= (fp_t)j; + } + y[0][i] = result; + } + return 0; +} + + |