Add Graph.load_g2o() classmethod and deprecate the load_g2o() standal…

…one function (#72)

README.rst

@@ -39,9 +39,9 @@ SE(3) Dataset
 
 .. code-block:: python
 
-   >>> from graphslam.load import load_g2o
+   >>> from graphslam.graph import Graph
 
-   >>> g = load_g2o("data/parking-garage.g2o")  # https://lucacarlone.mit.edu/datasets/
+   >>> g = Graph.load_g2o("data/parking-garage.g2o")  # https://lucacarlone.mit.edu/datasets/
 
    >>> g.plot(vertex_markersize=1)
 
@@ -79,9 +79,9 @@ SE(2) Dataset
 
 .. code-block:: python
 
-   >>> from graphslam.load import load_g2o
+   >>> from graphslam.graph import Graph
 
-   >>> g = load_g2o("data/input_INTEL.g2o")  # https://lucacarlone.mit.edu/datasets/
+   >>> g = Graph.load_g2o("data/input_INTEL.g2o")  # https://lucacarlone.mit.edu/datasets/
 
    >>> g.plot()
 

graphslam/edge/base_edge.py

@@ -163,8 +163,8 @@ def to_g2o(self):
 
         Returns
         -------
-        str
-            The edge in .g2o format
+        str, None
+            The edge in .g2o format, or ``None`` if writing to g2o format is not supported
 
         """
 
@@ -182,6 +182,7 @@ def from_g2o(cls, line):
         -------
         BaseEdge, None
             The instantiated edge object, or ``None`` if ``line`` does not correspond to this edge type
+            (or if this edge type does not support loading from g2o)
 
         """
 

graphslam/graph.py

@@ -77,6 +77,7 @@
 
 from collections import defaultdict
 from functools import reduce
+import logging
 import time
 import warnings
 
@@ -90,6 +91,12 @@
 except ImportError:  # pragma: no cover
     plt = None
 
+from .edge.base_edge import BaseEdge
+from .edge.edge_odometry import EdgeOdometry
+from .vertex import Vertex
+
+
+_LOGGER = logging.getLogger(__name__)
 
 warnings.simplefilter("ignore", SparseEfficiencyWarning)
 warnings.filterwarnings("ignore", category=SparseEfficiencyWarning)
@@ -512,6 +519,78 @@ def to_g2o(self, outfile):
                 if edge_str_or_none:
                     f.write(edge_str_or_none)
 
+    @classmethod
+    def load_g2o(cls, infile, custom_edge_types=None):
+        r"""Load a graph from a .g2o file.
+
+        Parameters
+        ----------
+        infile : str
+            The path to the .g2o file
+        custom_edge_types : list[type], None
+            A list of custom edge types, which must be subclasses of ``BaseEdge``
+
+        Returns
+        -------
+        Graph
+            The loaded graph
+
+        """
+        edges = []
+        vertices = []
+
+        custom_edge_types = custom_edge_types or []
+        for edge_type in custom_edge_types:
+            assert issubclass(edge_type, BaseEdge)
+
+        def custom_edge_from_g2o(line, custom_edge_types):
+            """Load a custom edge from a .g2o line.
+
+            Parameters
+            ----------
+            line : str
+                A line from a .g2o file
+            custom_edge_types : list[type]
+                A list of custom edge types, which must be subclasses of ``BaseEdge``
+
+            Returns
+            -------
+            BaseEdge, None
+                The instantiated edge object, or ``None`` if the line does not correspond to any of the custom edge types
+
+            """
+            for custom_edge_type in custom_edge_types:
+                edge_or_none = custom_edge_type.from_g2o(line)
+                if edge_or_none:
+                    return edge_or_none
+
+            return None
+
+        with open(infile) as f:
+            for line in f.readlines():
+                if line.strip():
+                    # Vertex
+                    vertex_or_none = Vertex.from_g2o(line)
+                    if vertex_or_none:
+                        vertices.append(vertex_or_none)
+                        continue
+
+                    # Custom edge types
+                    custom_edge_or_none = custom_edge_from_g2o(line, custom_edge_types)
+                    if custom_edge_or_none:
+                        edges.append(custom_edge_or_none)
+                        continue
+
+                    # Odometry Edge
+                    edge_or_none = EdgeOdometry.from_g2o(line)
+                    if edge_or_none:
+                        edges.append(edge_or_none)
+                        continue
+
+                    _LOGGER.warning("Line not supported -- '%s'", line.rstrip())
+
+        return cls(edges, vertices)
+
     def plot(self, vertex_color="r", vertex_marker="o", vertex_markersize=3, edge_color="b", title=None):
         """Plot the graph.
 

graphslam/load.py

@@ -7,10 +7,7 @@
 
 import logging
 
-from .edge.base_edge import BaseEdge
-from .edge.edge_odometry import EdgeOdometry
 from .graph import Graph
-from .vertex import Vertex
 
 
 _LOGGER = logging.getLogger(__name__)
@@ -32,60 +29,8 @@ def load_g2o(infile, custom_edge_types=None):
         The loaded graph
 
     """
-    edges = []
-    vertices = []
-
-    custom_edge_types = custom_edge_types or []
-    for edge_type in custom_edge_types:
-        assert issubclass(edge_type, BaseEdge)
-
-    def custom_edge_from_g2o(line, custom_edge_types):
-        """Load a custom edge from a .g2o line.
-
-        Parameters
-        ----------
-        line : str
-            A line from a .g2o file
-        custom_edge_types : list[type]
-            A list of custom edge types, which must be subclasses of ``BaseEdge``
-
-        Returns
-        -------
-        BaseEdge, None
-            The instantiated edge object, or ``None`` if the line does not correspond to any of the custom edge types
-
-        """
-        for custom_edge_type in custom_edge_types:
-            edge_or_none = custom_edge_type.from_g2o(line)
-            if edge_or_none:
-                return edge_or_none
-
-        return None
-
-    with open(infile) as f:
-        for line in f.readlines():
-            if line.strip():
-                # Vertex
-                vertex_or_none = Vertex.from_g2o(line)
-                if vertex_or_none:
-                    vertices.append(vertex_or_none)
-                    continue
-
-                # Custom edge types
-                custom_edge_or_none = custom_edge_from_g2o(line, custom_edge_types)
-                if custom_edge_or_none:
-                    edges.append(custom_edge_or_none)
-                    continue
-
-                # Odometry Edge
-                edge_or_none = EdgeOdometry.from_g2o(line)
-                if edge_or_none:
-                    edges.append(edge_or_none)
-                    continue
-
-                _LOGGER.warning("Line not supported -- '%s'", line.rstrip())
-
-    return Graph(edges, vertices)
+    _LOGGER.warning("load_g2o is deprecated; use Graph.load_g2o instead")
+    return Graph.load_g2o(infile, custom_edge_types)
 
 
 def load_g2o_r2(infile):
@@ -102,8 +47,8 @@ def load_g2o_r2(infile):
         The loaded graph
 
     """
-    _LOGGER.warning("load_g2o_r2 is deprecated; use load_g2o instead")
-    return load_g2o(infile)
+    _LOGGER.warning("load_g2o_r2 is deprecated; use Graphload_g2o instead")
+    return Graph.load_g2o(infile)
 
 
 def load_g2o_r3(infile):
@@ -120,8 +65,8 @@ def load_g2o_r3(infile):
         The loaded graph
 
     """
-    _LOGGER.warning("load_g2o_r3 is deprecated; use load_g2o instead")
-    return load_g2o(infile)
+    _LOGGER.warning("load_g2o_r3 is deprecated; use Graph.load_g2o instead")
+    return Graph.load_g2o(infile)
 
 
 def load_g2o_se2(infile):
@@ -138,8 +83,8 @@ def load_g2o_se2(infile):
         The loaded graph
 
     """
-    _LOGGER.warning("load_g2o_se2 is deprecated; use load_g2o instead")
-    return load_g2o(infile)
+    _LOGGER.warning("load_g2o_se2 is deprecated; use Graph.load_g2o instead")
+    return Graph.load_g2o(infile)
 
 
 def load_g2o_se3(infile):
@@ -156,5 +101,5 @@ def load_g2o_se3(infile):
         The loaded graph
 
     """
-    _LOGGER.warning("load_g2o_se3 is deprecated; use load_g2o instead")
-    return load_g2o(infile)
+    _LOGGER.warning("load_g2o_se3 is deprecated; use Graph.load_g2o instead")
+    return Graph.load_g2o(infile)

tests/edge_types.py

@@ -14,7 +14,8 @@ class BaseEdgeForTests(BaseEdge):
     """A base edge class for tests."""
 
     def to_g2o(self):
-        """Not supported, so don't do anything."""
+        """Not supported, so return ``None``."""
+        return None
 
     @classmethod
     def from_g2o(cls, line):

tests/test_custom_edge.py

@@ -25,7 +25,8 @@ class DistanceEdgeNumericalJacobians(BaseEdge):
     """
 
     def to_g2o(self):
-        """Not supported, so don't do anything."""
+        """Not supported, so return ``None``."""
+        return None
 
     @classmethod
     def from_g2o(cls, line):

tests/test_load.py

@@ -83,7 +83,7 @@ def test_load_g2o_r2(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o_r2("test.g2o")
             self.assertAlmostEqual(chi2, g2.calc_chi2())
 
@@ -99,7 +99,7 @@ def test_load_g2o_r3(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o_r3("test.g2o")
             self.assertAlmostEqual(chi2, g2.calc_chi2())
 
@@ -114,7 +114,7 @@ def test_load_g2o_se2(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o_se2("test.g2o")
             self.assertAlmostEqual(chi2, g2.calc_chi2())
 
@@ -129,7 +129,7 @@ def test_load_g2o_se3(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o_se3("test.g2o")
             self.assertAlmostEqual(chi2, g2.calc_chi2())
 
@@ -145,7 +145,7 @@ def test_load_custom_edge_without_to_g2o_without_from_g2o(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o("test.g2o")
             self.assertFalse(g.equals(g2))
 
@@ -161,7 +161,7 @@ def test_load_custom_edge_with_to_g2o_without_from_g2o(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o("test.g2o", [EdgeWithToG2OWithoutFromG2O])
             self.assertFalse(g.equals(g2))
 
@@ -177,7 +177,7 @@ def test_load_custom_edge_without_to_g2o_with_from_g2o(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o("test.g2o", [EdgeWithoutToG2OWithFromG2O])
             self.assertFalse(g.equals(g2))
 
@@ -193,6 +193,6 @@ def test_load_custom_edge_with_to_g2o_with_from_g2o(self):
         with mock.patch("graphslam.graph.open", open_fake_file):
             g.to_g2o("test.g2o")
 
-        with mock.patch("graphslam.load.open", open_fake_file):
+        with mock.patch("graphslam.graph.open", open_fake_file):
             g2 = load_g2o("test.g2o", [EdgeWithToG2OWithFromG2O])
             self.assertTrue(g.equals(g2))