1 files changed, 54 insertions, 0 deletions
diff --git a/lib/catalan.c b/lib/catalan.c
new file mode 100644
index 0000000..4a6ed9e
--- /dev/null
+++ b/lib/catalan.c
@@ -0,0 +1,54 @@
+// Catalan Number
+//
+// catalan - C(n)
+//
+// nth Catalan number: C(n) = (2n)! / ((n+1)! * n!)
+//
+// Inputs:    1 (n)
+// Outputs:   1 (Catalan number)
+// Constants: 0
+
+#include <math.h>
+#include "ts.h"
+
+
+
+ts_parameter_t const ts_catalan_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };
+
+
+uint_t ts_catalan_offset( ts_constant_t const *c )
+{
+	( void )c;
+	return ( 0 );
+}
+
+int ts_catalan(
+	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_catalan_p );
+	(void)c;
+	for( uint_t i = 0; i < n; ++i )
+	{
+		fp_t xv = x[0][i];
+		if (isnan(xv) || isinf(xv) || xv < 0 || xv != (fp_t)(uint_t)xv) {
+			y[0][i] = 0;
+			continue;
+		}
+		uint_t n_val = (uint_t)xv;
+		fp_t result = 1.0;
+		for( uint_t j = 0; j < n_val; ++j )
+		{
+			result *= (fp_t)(j + n_val + 1);
+			result /= (fp_t)(j + 1);
+		}
+		result /= (fp_t)(n_val + 1);
+		y[0][i] = result;
+	}
+	return 0;
+}
+
+
+