From 07e18043145f3d91c8ea7ec3ad41b3c905585277 Mon Sep 17 00:00:00 2001
From: Ethan Werner <mail@ethanwerner.com>
Date: Wed, 1 Jul 2026 09:42:39 +0400
Subject: 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
---
 lib/ratio.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100755 lib/ratio.c

(limited to 'lib/ratio.c')

diff --git a/lib/ratio.c b/lib/ratio.c
new file mode 100755
index 0000000..8568476
--- /dev/null
+++ b/lib/ratio.c
@@ -0,0 +1,49 @@
+// Ratio
+//
+// ratio - ratio
+//
+// Calculates the ratio between the current value and the value k samples ago
+//
+// y_i = x_i / x_i-k
+//
+// Inputs:    1
+// Outputs:   1
+// Constants: 0
+
+
+#include "ts.h"
+
+
+typedef struct {
+    uint_t k;
+} ts_ratio_params_t;
+
+ts_parameter_t const ts_ratio_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 1, .params_size = sizeof(ts_ratio_params_t) };
+
+
+uint_t ts_ratio_offset( ts_constant_t const *c )
+{
+	( void )c;
+	return ( c ? ((ts_ratio_params_t *)c)->k : 0 );
+}
+
+int ts_ratio(
+	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_ratio_p );
+	if ( !c ) return -1;
+	uint_t k = ((ts_ratio_params_t *)c)->k;
+	if (k == 0 || n < k) return -1;
+	
+	uint_t xi = k;
+
+	for( ; xi < n; xi++ )
+	{
+		if( x[0][xi - k] == 0 ) { y[0][xi] = 0; } else { y[0][xi] = x[0][xi] / x[0][xi - k]; }
+	}
+	return 0;
+}
+
-- 
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