Resolving minor bug in StreamLines (#2330)

* resolving minor bug in StreamLines

* minute changes

Author: Varniex

manimlib/config.py

@@ -257,7 +257,7 @@ def update_camera_config(config: Dict, args: Namespace):
     if args.color:
         try:
             camera_config.background_color = colour.Color(args.color)
-        except Exception:
+        except Exception as err:
             log.error("Please use a valid color")
             log.error(err)
             sys.exit(2)

manimlib/mobject/vector_field.py

@@ -390,7 +390,6 @@ def point_func(self, points: Vect3Array) -> Vect3:
 
     def draw_lines(self) -> None:
         lines = []
-        origin = self.coordinate_system.get_origin()
 
         # Todo, it feels like coordinate system should just have
         # the ODE solver built into it, no?
@@ -426,7 +425,7 @@ def init_style(self) -> None:
             cs = self.coordinate_system
             for line in self.submobjects:
                 norms = [
-                    get_norm(self.func(*cs.p2c(point)))
+                    get_norm(self.func(cs.p2c(point)))
                     for point in line.get_points()
                 ]
                 rgbs = values_to_rgbs(norms)
@@ -471,7 +470,7 @@ def __init__(
 
         self.add_updater(lambda m, dt: m.update(dt))
 
-    def update(self, dt: float) -> None:
+    def update(self, dt: float = 0) -> None:
         stream_lines = self.stream_lines
         for line in stream_lines:
             line.time += dt