diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..720fdd6
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,15 @@
+FROM ubuntu:20.04
+ENV PIP_BREAK_SYSTEM_PACKAGES 1
+ENV PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
+
+RUN apt-get update
+RUN DEBIAN_FRONTEND=noninteractive TZ=Etc/UTC apt-get -y install tzdata parallel
+RUN apt install --assume-yes git python3 python3-pip pkg-config build-essential wget
+RUN pip3 install matplotlib
+RUN git clone https://github.com/cgroza/graph_peak_caller.git \
+RUN cd graph_peak_caller  && pip3 install .
+
+RUN wget https://github.com/vgteam/vg/releases/download/v1.58.0/vg -O /usr/bin/vg
+RUN chmod +x /usr/bin/vg
+
+ENTRYPOINT [ "/bin/bash", "-l", "-c" ]
diff --git a/graph_peak_caller/analysis/util.py b/graph_peak_caller/analysis/util.py
index 11379ba..ff0c6e7 100644
--- a/graph_peak_caller/analysis/util.py
+++ b/graph_peak_caller/analysis/util.py
@@ -46,6 +46,9 @@ def get_linear_paths_in_graph(ob_graph, vg_graph, write_to_file_name=None):
     intervals = {}
     for path in vg_graph.paths:
         obg_interval = path.to_obg(ob_graph=ob_graph)
+        if not obg_interval:
+            logging.info("OBG interval for path " + path.name + " is False. Skipping.")
+            continue
         obg_interval.name = path.name
         print("Path name: %s" % path.name)
         intervals[obg_interval.name] = obg_interval
diff --git a/graph_peak_caller/callpeaks.py b/graph_peak_caller/callpeaks.py
index affd1e5..078bf89 100644
--- a/graph_peak_caller/callpeaks.py
+++ b/graph_peak_caller/callpeaks.py
@@ -191,7 +191,7 @@ def __get_max_paths(self):
             assert max_path.length() >= 0, "Max path %s has negative length" % max_path
             if max_path.length() == 0:
                 logging.warning("Max path has 0 length: %s" % max_path)
-                max_path.set_score(0)
+                max_path.set_score(float(0.0))
                 continue
 
             score = np.max(self.q_values.get_interval_values(max_path))
diff --git a/graph_peak_caller/control/linearmap.py b/graph_peak_caller/control/linearmap.py
index 9bae0f6..dc8312b 100644
--- a/graph_peak_caller/control/linearmap.py
+++ b/graph_peak_caller/control/linearmap.py
@@ -120,7 +120,10 @@ def to_file(self, filename):
     def find_starts(graph, node_ids=None):
         if node_ids is None:
             node_ids = list(graph.get_topological_sorted_node_ids())
-        max_dists = np.zeros(len(node_ids))
+        # this does not work for node id spaces that are not compactec
+        # max_dists = np.zeros(len(node_ids))
+        # find size of array from the largest named node instead
+        max_dists = np.zeros(int(graph.get_sorted_node_ids()[-1]))
         n_processed = 0
         for node_id in node_ids:
             if n_processed % 500000 == 0:
@@ -139,7 +142,10 @@ def find_ends(graph, node_ids=None):
         adj_list = graph.reverse_adj_list
         if node_ids is None:
             node_ids = list(graph.get_sorted_node_ids(reverse=True))
-        max_dists = np.zeros(len(node_ids))
+        # this does not work for node id spaces that are not compactec
+        # max_dists = np.zeros(len(node_ids))
+        # find size of array from the largest named node instead
+        max_dists = np.zeros(int(graph.get_sorted_node_ids()[-1]))
         n_processed = 0
         for node_id in node_ids:
             if n_processed % 500000 == 0:
diff --git a/graph_peak_caller/legacy/pvalues.py b/graph_peak_caller/legacy/pvalues.py
index fb0823d..3c6a8ad 100644
--- a/graph_peak_caller/legacy/pvalues.py
+++ b/graph_peak_caller/legacy/pvalues.py
@@ -127,6 +127,6 @@ def translation(x):
                 logging.error("P value not found in mapping dict. Could be due to rounding errors.")
             return self.p_to_q_values[x]
 
-        trans = np.vectorize(translation, otypes=[np.float])
+        trans = np.vectorize(translation, otypes=[float])
         new_values = trans(p_values)
         return new_values
diff --git a/graph_peak_caller/sparsediffs.py b/graph_peak_caller/sparsediffs.py
index 827a738..eccfa24 100644
--- a/graph_peak_caller/sparsediffs.py
+++ b/graph_peak_caller/sparsediffs.py
@@ -62,7 +62,7 @@ def threshold_copy(self, cutoff):
         return new
 
     def to_dense_pileup(self, size):
-        if self.values.dtype == np.bool:
+        if self.values.dtype == bool:
             values = self.values.astype("int")
         else:
             values = self.values
diff --git a/graph_peak_caller/sparsepvalues.py b/graph_peak_caller/sparsepvalues.py
index 3e39969..cf63873 100644
--- a/graph_peak_caller/sparsepvalues.py
+++ b/graph_peak_caller/sparsepvalues.py
@@ -121,5 +121,5 @@ def get_q_values(self):
 
     def get_q_array_from_p_array(self, p_values):
         assert isinstance(p_values, np.ndarray)
-        trans = np.vectorize(self.p_to_q_values.get, otypes=[np.float])
+        trans = np.vectorize(self.p_to_q_values.get, otypes=[float])
         return trans(p_values)