1 files changed, 38 insertions, 0 deletions
diff --git a/lib/exponential_pdf.c b/lib/exponential_pdf.c
new file mode 100644
index 0000000..ccb942a
--- /dev/null
+++ b/lib/exponential_pdf.c
@@ -0,0 +1,38 @@
+// Exponential PDF
+//
+// exponential_pdf - exponential probability density
+//
+// f(x) = e^(-x) for x >= 0, else 0
+//
+// Inputs:    1
+// Outputs:   1 (PDF value)
+// Constants: 0
+
+#include <math.h>
+#include "ts.h"
+
+
+ts_parameter_t const ts_exponential_pdf_p = { .n_inputs = 1, .n_outputs = 1, .n_constants = 0, .params_size = 0 };
+
+uint_t ts_exponential_pdf_offset( ts_constant_t const *c )
+{
+	( void )c;
+	return ( 0 );
+}
+
+int ts_exponential_pdf(
+	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_exponential_pdf_p );
+	(void)c;
+	for( uint_t i = 0; i < n; ++i )
+	{
+		y[0][i] = x[0][i] >= 0 ? exp( -x[0][i] ) : 0.0;
+	}
+	return 0;
+}
+
+