diff --git a/stim/structures/kdtree.cuh b/stim/structures/kdtree.cuh
index 093c71a..c21492e 100644
--- a/stim/structures/kdtree.cuh
+++ b/stim/structures/kdtree.cuh
@@ -347,6 +347,10 @@ namespace stim {
 			}
 		}
 		
+		/// create a KD-tree given a pointer to an array of reference points and the number of reference points
+		/// @param h_reference_points is a host array containing the reference points in (x0, y0, z0, ...., ) order
+		/// @param reference_count is the number of reference point in the array	 
+		/// @param max_levels is the deepest number of tree levels allowed
 		void create(T *h_reference_points, size_t reference_count, size_t max_levels) {
 			#ifdef __CUDACC__
 			if (max_levels > 10) {
@@ -552,6 +556,11 @@ namespace stim {
 			}
 		}
 
+		/// search the KD tree for nearest neighbors to a set of specified query points
+		/// @param h_query_points an array of query points in (x0, y0, z0, ...) order 
+		/// @param query_count is the number of query points 
+		/// @param indices are the indices to the nearest reference point for each query points 
+		/// @param distances is an array containing the distance between each query point and the nearest reference point
 		void search(T *h_query_points, size_t query_count, size_t *indices, T *distances) {
 			#ifdef __CUDACC__
 			std::vector < typename cpu_kdtree::point<T, D> > query_points(query_count);
diff --git a/stim/visualization/cylinder.h b/stim/visualization/cylinder.h
index 06ae2ee..6e6a1ff 100644
--- a/stim/visualization/cylinder.h
+++ b/stim/visualization/cylinder.h
@@ -68,7 +68,7 @@ public:
 	///Returns the ith magnitude at the given p-value (p value ranges from 0 to 1).
 	///interpolates the radius along the line.
 	///@param pvalue: the location of the in the cylinder, from 0 (beginning to 1).
-	T r(T pvalue) {
+	T rl(T pvalue) {
 		if (pvalue <= 0.0) return R[0];
 		if (pvalue >= 1.0) return R[size() - 1];
 
@@ -80,9 +80,9 @@ public:
 	///	Returns the magnitude at the given index
 	///	@param i is the index of the desired point
 	/// @param r is the index of the magnitude value
-	//T r(unsigned i) {
-	//	return R[i];
-	//}
+	T r(unsigned i) {
+		return R[i];
+	}
 
 	///adds a magnitude to each point in the cylinder
 	/*void add_mag(V val = 0) {
--
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