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authorEthan Werner <mail@ethanwerner.com>2026-07-01 09:42:39 +0400
committerEthan Werner <mail@ethanwerner.com>2026-07-01 09:42:39 +0400
commit07e18043145f3d91c8ea7ec3ad41b3c905585277 (patch)
tree2bdeae46973f4bdfce263679a4008ac768011f28 /lib/reversal.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/reversal.c')
-rw-r--r--lib/reversal.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/lib/reversal.c b/lib/reversal.c
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+// Reversal
+//
+// reversal
+//
+// Reversal indicator
+//
+//
+//
+// Inputs: 1
+// Outputs: 1
+// Constants: 0
+
+
+#include "ts.h"
+
+
+ts_parameter_t const ts_reversal_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };
+
+uint_t ts_reversal_offset( ts_constant_t const *c )
+{
+ ( void )c;
+ return ( 2 );
+}
+
+int ts_reversal(
+ 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_reversal_p );
+ (void)c;
+ if (n > 0) y[0][0] = 0;
+ if (n > 1) y[0][1] = 0;
+ for( uint_t i = 2; i < n; ++i )
+ {
+ if( x[0][i] < x[0][i - 1] && x[0][i - 1] > x[0][i - 2] )
+ {
+ y[0][i] = -1;
+ }
+ else if( x[0][i] > x[0][i - 1] && x[0][i - 1] < x[0][i - 2] )
+ {
+ y[0][i] = 1;
+ }
+ else
+ {
+ y[0][i] = 0;
+ }
+ }
+ return 0;
+}
+