1 files changed, 47 insertions, 0 deletions
diff --git a/lib/hard_sigmoid.c b/lib/hard_sigmoid.c
new file mode 100644
index 0000000..f54d4af
--- /dev/null
+++ b/lib/hard_sigmoid.c
@@ -0,0 +1,47 @@
+// Hard Sigmoid
+//
+// hard_sigmoid - Hard Sigmoid activation
+//
+// y[t] = x[t] <= -3 ? 0 : x[t] >= 3 ? 1 : x[t]/6 + 0.5
+//
+// X_n - 1
+// Y_n - 1
+// C_n - 0
+
+
+#include "ts.h"
+
+
+
+ts_parameter_t const ts_hard_sigmoid_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };
+
+
+uint_t ts_hard_sigmoid_offset( ts_constant_t const *c )
+{
+	( void )c;
+	return ( 0 );
+}
+
+int ts_hard_sigmoid(
+	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_hard_sigmoid_p );
+	(void)c;
+	for( uint_t i = 0; i < n; ++i )
+	{
+		fp_t xi = x[0][i];
+		if ( xi <= -3 )
+			y[0][i] = 0;
+		else if ( xi >= 3 )
+			y[0][i] = 1;
+		else
+			y[0][i] = xi / 6 + 0.5;
+	}
+	return 0;
+}
+
+
+