fix:muscular snake scale dissipation

examples/MuscularSnake/muscular_snake.py

@@ -1,6 +1,6 @@
 __doc__ = """Muscular snake example from Zhang et. al. Nature Comm 2019 paper."""
 import sys
-
+import numpy as np
 sys.path.append("../../")
 from elastica import *
 from examples.MuscularSnake.post_processing import (
@@ -54,7 +54,7 @@ class MuscularSnakeSimulator(
     base_length_body,
     base_radius_body,
     density_body,
-    nu,
+    nu/ density_body / (np.pi*base_radius_body**2),
     youngs_modulus=E,
     shear_modulus=shear_modulus,
 )
@@ -100,6 +100,7 @@ class MuscularSnakeSimulator(
 muscle_radius = np.zeros((n_elem_muscle_group_one_to_three))
 muscle_radius[:] = 0.003  # First set tendon radius for whole rod.
 muscle_radius[4 * 3 : 9 * 3] = 0.006  # Change the radius of muscle elements
+nu_muscle /= density_muscle * np.pi * 0.003**2
 
 for i in range(int(n_muscle_fibers / 2)):