diff --git a/docs/0_getting_started.rst b/docs/0_getting_started.rst
index cac6b5b..293d53f 100644
--- a/docs/0_getting_started.rst
+++ b/docs/0_getting_started.rst
@@ -20,7 +20,7 @@ Installation with pip:
 Dependencies
 ------------
 
-(``python3.6+``),``numpy``
+(``python3.6+``), ``numpy``
 
 
 
diff --git a/docs/4_api.rst b/docs/4_api.rst
index a786009..8a8f230 100644
--- a/docs/4_api.rst
+++ b/docs/4_api.rst
@@ -13,3 +13,12 @@ API documentation
 PolygonEnvironment
 ------------------
 .. autoclass:: PolygonEnvironment
+
+
+.. py:module:: extremitypathfinder.plotting
+
+PlottingEnvironment
+-------------------
+.. autoclass:: PlottingEnvironment
+   :members: store, prepare, find_shortest_path
+   :no-inherited-members:
diff --git a/docs/requirements_docs.txt b/docs/requirements_docs.txt
index cae37e9..aa19de0 100644
--- a/docs/requirements_docs.txt
+++ b/docs/requirements_docs.txt
@@ -2,3 +2,4 @@
 # python3.6+
 numpy>=1.16
 sphinx_rtd_theme
+matplotlib
diff --git a/extremitypathfinder/plotting.py b/extremitypathfinder/plotting.py
index 733f460..9cd6c0e 100644
--- a/extremitypathfinder/plotting.py
+++ b/extremitypathfinder/plotting.py
@@ -195,6 +195,9 @@ def draw_graph(map, graph):
 
 
 class PlottingEnvironment(PolygonEnvironment):
+    """Extends PolygonEnvironment. In addition to the base functionality it
+    plots graphs of the polygons, the visibility graph and the computed path.
+    Stores all graphs in the folder defined by plotting_dir parameter."""
     def __init__(self, plotting_dir=PLOTTING_DIR):
         super().__init__()
         global PLOTTING_DIR
@@ -203,14 +206,17 @@ def __init__(self, plotting_dir=PLOTTING_DIR):
             makedirs(plotting_dir)
 
     def store(self, *args, **kwargs):
+        """In addition to storing, also plots a graph of the input polygons."""
         super().store(*args, **kwargs)
         draw_loaded_map(self)
 
     def prepare(self):
+        """Also draws a prepared map with the computed visibility graph."""
         super().prepare()
         draw_prepared_map(self)
 
     def find_shortest_path(self, *args, **kwargs):
+        """Also draws the computed shortest path."""
         # important to not delete the temp graph! for plotting
         vertex_path, distance = super().find_shortest_path(
             *args, free_space_after=False, **kwargs
diff --git a/requirements.txt b/requirements.txt
index 2549ae4..267f350 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
 # basic dependencies:
 # python3.7+
 numpy>=1.16
+matplotlib