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

1 files changed, 41 insertions, 0 deletions

diff --git a/lib/secant.c b/lib/secant.c
new file mode 100644
index 0000000..128e5a7
--- /dev/null
+++ b/lib/secant.c
@@ -0,0 +1,41 @@
+// Secant
+//
+// secant - sec
+//
+// f( x ) = sec( x )  = 1 / cos( x )
+//
+// X_n - 1
+// Y_n - 1
+// C_n - 0
+
+
+#include <math.h>
+#include "ts.h"
+
+
+
+ts_parameter_t const ts_secant_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };
+
+
+uint_t ts_secant_offset( ts_constant_t const *c )
+{
+	( void )c;
+	return ( 0 );
+}
+
+int ts_secant(
+	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_secant_p );
+	(void)c;
+	for( uint_t i = 0; i < n; ++i )
+	{
+		fp_t cv = cos( x[0][i] );
+		y[0][i] = ( fabs( cv ) > 1e-15 ) ? _ts_reciprocal( cv ) : ( cv > 0 ? (fp_t)INFINITY : (fp_t)-INFINITY );
+	}
+	return 0;
+}
+