up

Author: walchko

mdh/__init__.py

@@ -1,6 +1,8 @@
 try:
+    # 3.8
     from importlib.metadata import version # type: ignore
 except ImportError:
+    # <= 3.7
     from importlib_metadata import version # type: ignore
 
 # will this work?

mdh/arm.py

@@ -20,13 +20,15 @@ class KinematicChain(Sized, Iterable):
     _links = attr.ib(type=Sequence[Any])
 
     def __len__(self):
+        """Enables the length function, returns number links"""
         return len(self._links)
 
     def __iter__(self):
+        """Enables iteration of joints:  for j in chain: print(j)"""
         for l in self._links:
             yield l
 
-    def transform(self, joints: Sequence[float]):
+    def transform(self, joints):
         """Calculates the transformation and returns a 4x4 matrix"""
         if len(joints) != len(self._links):
             raise Exception("inputs don't equal number of links")
@@ -39,7 +41,7 @@ def transform(self, joints: Sequence[float]):
             # t = np.dot(m, t)
         return t
 
-    def forward(self, joints: Sequence[float]):
+    def forward(self, joints):
         """value?
         Solve the forward kinematics and returns a 4x4 matrix
         """

mdh/kinematic_chain.py

@@ -6,19 +6,19 @@
 JointType =  IntFlag('JointType', 'revolute prismatic revolute_theda revolute_alpha')
 mdh_params = namedtuple("mdh_params", "alpha a theta d type")
 
-@attr.s
-class Link:
-    """
-    why? what is the value of this?
-    prismatic/revolute have parameters that never chance ... need to freeze them!
-    """
-    # alpha = attr.ib(type=float)
-    # a = attr.ib(type=float)
-    # theta = attr.ib(type=float)
-    # d = attr.ib(type=float)
+# @attr.s
+# class Link:
+#     """
+#     why? what is the value of this?
+#     prismatic/revolute have parameters that never chance ... need to freeze them!
+#     """
+#     # alpha = attr.ib(type=float)
+#     # a = attr.ib(type=float)
+#     # theta = attr.ib(type=float)
+#     # d = attr.ib(type=float)
 
-@attr.s
-class RevoluteLink(Link):
+@attr.s(slots=True)
+class RevoluteLink:
     """
     RevoluteLink about theta. All other parameters (alpha, a, d) are fixed and
     cannot be changed once the link is created.
@@ -27,6 +27,8 @@ class RevoluteLink(Link):
     _a = attr.ib(type=float)
     theta = attr.ib(type=float)
     _d = attr.ib(type=float)
+    min = attr.ib(-np.pi, type=float)
+    max = attr.ib(np.pi, type=float)
 
     @property
     def alpha(self) -> float:
@@ -40,9 +42,9 @@ def a(self) -> float:
     def d(self) -> float:
         return self._d
 
-    # max/min limits of link for optimzation
-    min = attr.ib(-np.pi, type=float)
-    max = attr.ib(np.pi, type=float)
+    @property
+    def type(self):
+        return JointType.revolute
 
     """Some of these params are immutable, how do I do that?"""
     def transform(self, angle: float):
@@ -69,7 +71,11 @@ def transform(self, angle: float):
 
         return transform
 
-@attr.s
-class Prismatic(Link):
-    min = attr.ib(type=float)
-    max = attr.ib(type=float)
+# @attr.s
+# class Prismatic:
+#     min = attr.ib(type=float)
+#     max = attr.ib(type=float)
+#
+#     @property
+#     def type(self):
+#         return JointType.revolute

mdh/leg.py

@@ -16,6 +16,7 @@ classifiers = [
     'Operating System :: OS Independent',
     'Programming Language :: Python :: 3.6',
     'Programming Language :: Python :: 3.7',
+    'Programming Language :: Python :: 3.8',
     'Topic :: Software Development :: Libraries',
     'Topic :: Software Development :: Libraries :: Python Modules',
     'Topic :: Software Development :: Libraries :: Application Frameworks'
@@ -28,11 +29,12 @@ classifiers = [
 python = ">=3.6"
 numpy = ">=1.9"
 scipy = ">=1.0"
-attrs = ">=19.0"
+importlib-metadata = {version="*", python="<3.8"}
+# attrs = ">=19.0"
 
 [tool.poetry.dev-dependencies]
 pytest = "^5.2"
-mypy = "*"
+# mypy = "*"
 
 [build-system]
 requires = ["poetry>=0.12"]

mdh/link.py

@@ -23,8 +23,8 @@ You should probably use one of these, they inspired me to write a simpler
 module for my needs:
 
 - [pybotics](https://github.com/nnadeau/pybotics)
-- [pytransform3d](https://github.com/rock-learning/pytransform3d)
-- [robopy](https://github.com/MultipedRobotics/robopy)
+- [pytransform3d](https://github.com/rock-learning/pytransform3d), some matplotlib 3d examples
+- [robopy](https://github.com/adityadua24/robopy), has some good matplotlib 3d examples, but seems rather brittle and difficult to work with
 - [tinyik](https://github.com/lanius/tinyik), uses `open3d` to visualize the mechanism
 
 ## Example

poetry.lock

@@ -1,7 +1,9 @@
 import pytest
+import mdh
+from mdh.models import puma500
 
-def test_dummy():
-    assert True
+# def test_dummy():
+#     assert True
 
 # @pytest.mark.xfail
 # def test_dummy_2():