tool and base can be None

petercorke · petercorke · commit 7c64cbb9be50 · 2020-10-11T09:06:49.000+10:00
rather than default value of SE3()
helps for symbolic stuff
diff --git a/roboticstoolbox/robot/Robot.py b/roboticstoolbox/robot/Robot.py
@@ -20,10 +20,6 @@ def __init__(
         self.name = name
         self.manufacturer = manufacturer
 
-        if base is None:
-            base = SE3()
-        if tool is None:
-            tool = SE3()
         self.base = base
         self.tool = tool
         if keywords is not None and not isinstance(keywords, (tuple, list)):
@@ -96,15 +92,22 @@ def manufacturer(self, manufacturer_new):
 
     @base.setter
     def base(self, T):
-        if not isinstance(T, SE3):
-            T = SE3(T)
-        self._base = T
+        # if not isinstance(T, SE3):
+        #     T = SE3(T)
+        if T is None or isinstance(T, SE3):
+            self._base = T
+        else:
+            raise ValueError('base must be set to None (no tool) or an SE3')
 
     @tool.setter
     def tool(self, T):
-        if not isinstance(T, SE3):
-            T = SE3(T)
-        self._tool = T
+        # if not isinstance(T, SE3):
+        #     T = SE3(T)
+        # this is allowed to be none, it's helpful for symbolics rather than having an identity matrix
+        if T is None or isinstance(T, SE3):
+            self._tool = T
+        else:
+            raise ValueError('tool must be set to None (no tool) or an SE3')
 
     @gravity.setter
     def gravity(self, gravity_new):
