diff --git a/src/lib.rs b/src/lib.rs
index 39d4350..ce8b50b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,6 @@
 pub use self::pdm::PDM;
 
-mod pdm;
+pub mod pdm;
 
 #[cfg(feature = "python")]
 pub mod python;
diff --git a/src/pdm.rs b/src/pdm.rs
index a6f9197..612664d 100644
--- a/src/pdm.rs
+++ b/src/pdm.rs
@@ -25,19 +25,19 @@ use crate::util::{create_row_vec_from_mat_dims, row_idx_from_mat_coords, row_vec
 /// ```
 #[derive(Default)]
 pub struct PDM {
-    pub(crate) nodes: Vec<Node>,
-    pub(crate) taxon_to_node_id: HashMap<Taxon, NodeId>,
-    pub(crate) leaf_idx_to_row_idx: HashMap<NodeId, usize>,
-    pub(crate) leaf_idx_to_row_idx_vec: Vec<usize>,
-    pub(crate) row_idx_to_leaf_idx: Vec<NodeId>,
-    pub(crate) nodes_at_depth: HashMap<NodeDepth, Vec<NodeId>>,
-    pub(crate) row_vec: Option<Vec<f64>>,
+    pub nodes: Vec<Node>,
+    pub taxon_to_node_id: HashMap<Taxon, NodeId>,
+    pub leaf_idx_to_row_idx: HashMap<NodeId, usize>,
+    pub leaf_idx_to_row_idx_vec: Vec<usize>,
+    pub row_idx_to_leaf_idx: Vec<NodeId>,
+    pub nodes_at_depth: HashMap<NodeDepth, Vec<NodeId>>,
+    pub row_vec: Option<Vec<f64>>,
 }
 
 impl PDM {
     /// Return the number of nodes (leaf + internal) in the tree.
     #[must_use]
-    fn n_nodes(&self) -> usize {
+    pub fn n_nodes(&self) -> usize {
         self.nodes.len()
     }
 
@@ -68,7 +68,7 @@ impl PDM {
     }
 
     /// Returns a vector of node indices at a specific depth. Errors if depth doesn't exist.
-    fn get_node_idxs_at_depth(&self, depth: NodeDepth) -> Result<Vec<NodeId>, PhyloErr> {
+    pub fn get_node_idxs_at_depth(&self, depth: NodeDepth) -> Result<Vec<NodeId>, PhyloErr> {
         if self.nodes_at_depth.get(&depth).is_none() {
             return Err(PhyloErr("No nodes at depth! Please report this error.".to_string()));
         }
@@ -90,13 +90,13 @@ impl PDM {
 
     /// Returns the row vector index for a given leaf node id.
     #[must_use]
-    fn get_row_vec_idx_from_leaf_idx(&self, leaf_id: NodeId) -> usize {
+    pub fn get_row_vec_idx_from_leaf_idx(&self, leaf_id: NodeId) -> usize {
         self.leaf_idx_to_row_idx_vec[leaf_id.0]
     }
 
     /// Get the row vector index for two taxa in the tree.
     #[must_use]
-    fn get_row_vec_idx_dist_between_leaf_idx(&self, i: NodeId, j: NodeId) -> usize {
+    pub fn get_row_vec_idx_dist_between_leaf_idx(&self, i: NodeId, j: NodeId) -> usize {
         let n_taxa = self.n_leaf_nodes();
         let i_idx = self.get_row_vec_idx_from_leaf_idx(i);
         let j_idx = self.get_row_vec_idx_from_leaf_idx(j);
@@ -105,7 +105,7 @@ impl PDM {
 
     /// Add a new leaf node to the tree.
     /// Returns the ID of the new node.
-    fn add_leaf_node(&mut self, taxon: &Taxon) -> Result<NodeId, PhyloErr> {
+    pub fn add_leaf_node(&mut self, taxon: &Taxon) -> Result<NodeId, PhyloErr> {
         // Panic if the taxon is already in the tree.
         if self.taxon_to_node_id.contains_key(taxon) {
             return Err(PhyloErr(format!("Taxon already exists in the tree: '{taxon:?}'")));
@@ -121,14 +121,14 @@ impl PDM {
     }
 
     /// Add a new internal node to the tree.
-    fn add_internal_node(&mut self) -> NodeId {
+    pub fn add_internal_node(&mut self) -> NodeId {
         let node_id = NodeId(self.n_nodes());
         self.nodes.push(Node::new(node_id, None));
         return self.nodes.last().unwrap().id;
     }
 
     /// Add a node to the tree.
-    pub(crate) fn add_node(&mut self, taxon: Option<&Taxon>) -> Result<NodeId, PhyloErr> {
+    pub fn add_node(&mut self, taxon: Option<&Taxon>) -> Result<NodeId, PhyloErr> {
         match taxon {
             Some(t) => self.add_leaf_node(t),
             None => Ok(self.add_internal_node()),
@@ -137,13 +137,13 @@ impl PDM {
 
     /// Retrieve a node from the tree.
     #[must_use]
-    fn get_node(&self, node_id: NodeId) -> &Node {
+    pub fn get_node(&self, node_id: NodeId) -> &Node {
         &self.nodes[node_id.0]
     }
 
     /// Retrieve a mutable node from the tree.
     #[must_use]
-    fn get_node_mut(&mut self, node_id: NodeId) -> &mut Node {
+    pub fn get_node_mut(&mut self, node_id: NodeId) -> &mut Node {
         &mut self.nodes[node_id.0]
     }
 
@@ -155,13 +155,13 @@ impl PDM {
     /// * `child`:  - `NodeId` of the child node.
     /// * `length`: - The branch length between these nodes.
     ///
-    pub(crate) fn add_edge(&mut self, parent: NodeId, child: NodeId, length: Edge) {
+    pub fn add_edge(&mut self, parent: NodeId, child: NodeId, length: Edge) {
         self.get_node_mut(parent).add_child(child);
         self.get_node_mut(child).set_parent(parent, length);
     }
 
     /// Set the depth of each node in the tree.
-    fn assign_node_depth(&mut self) -> Result<(), PhyloErr> {
+    pub fn assign_node_depth(&mut self) -> Result<(), PhyloErr> {
         // Iterate over each node to make sure there is only one root node.
         let mut root = None;
         for node in &self.nodes {
@@ -183,7 +183,7 @@ impl PDM {
     }
 
     /// Set the depth of all nodes using a depth first search.
-    fn set_node_depth_dfs(&mut self, root_id: NodeId) -> Result<(), PhyloErr> {
+    pub fn set_node_depth_dfs(&mut self, root_id: NodeId) -> Result<(), PhyloErr> {
         let mut nodes_at_depth: HashMap<NodeDepth, Vec<NodeId>> = HashMap::new();
 
         // Seed the stack with the root node.
@@ -236,7 +236,7 @@ impl PDM {
     }
 
     /// Wrapper method to calculate the pairwise distances at a given depth.
-    fn calculate_distances_at_depth(&mut self, depth: NodeDepth, row_vec: &mut [f64]) -> Result<(), PhyloErr> {
+    pub fn calculate_distances_at_depth(&mut self, depth: NodeDepth, row_vec: &mut [f64]) -> Result<(), PhyloErr> {
         // Iterate over all nodes a this depth
         for &node_id in &self.get_node_idxs_at_depth(depth)? {
             let node = self.get_node(node_id);
@@ -274,7 +274,7 @@ impl PDM {
 
     /// For a given node, iterate over its children and unset the descendant distances.
     /// This is mainly to free memory during distance matrix calculation.
-    fn unset_node_child_distances(&mut self, node_id: NodeId) {
+    pub fn unset_node_child_distances(&mut self, node_id: NodeId) {
         self.get_node(node_id)
             .children
             .clone()
@@ -287,7 +287,7 @@ impl PDM {
     /// This function sets the descendant distances for a given node.
     /// Note: This is only the distances to all descendant nodes (including leaf nodes).
     /// The pairwise leaf distances are calculated in another method.
-    fn set_node_descendant_distance(&mut self, node_id: NodeId) {
+    pub fn set_node_descendant_distance(&mut self, node_id: NodeId) {
         let mut node_desc_distances: HashMap<NodeId, Edge> = HashMap::new();
 
         let node = self.get_node(node_id);
@@ -311,7 +311,7 @@ impl PDM {
 
     /// This function calculates the pairwise distances to all leaf nodes.
     /// Assumes that the memory has not been freed for the mapping.
-    fn calc_pairwise_distances_to_leaf_nodes(&self, node_id: NodeId, row_vec: &mut [f64]) {
+    pub fn calc_pairwise_distances_to_leaf_nodes(&self, node_id: NodeId, row_vec: &mut [f64]) {
         let node = self.get_node(node_id);
         let children_idxs = &node.children;
 
@@ -353,7 +353,7 @@ impl PDM {
     }
 
     /// Orders the leaf nodes for reproducibility.
-    fn order_leaf_node_idx(&mut self) {
+    pub fn order_leaf_node_idx(&mut self) {
         let mut new_leaf_idx_to_row_idx: HashMap<NodeId, usize> = HashMap::with_capacity(self.n_leaf_nodes());
         let mut new_row_idx_to_leaf_idx: Vec<NodeId> = vec![NodeId::default(); self.n_leaf_nodes()];
 
@@ -465,7 +465,7 @@ impl PDM {
         Ok(())
     }
 
-    fn get_taxon_node_idx(&self, taxon: &Taxon) -> NodeId {
+    pub fn get_taxon_node_idx(&self, taxon: &Taxon) -> NodeId {
         self.taxon_to_node_id[taxon]
     }