text: """Use array to vary radius and color
  of a line represented as a tube"""
  from vedo import *
  import numpy as np
  
  settings.defaultFont = 'Quikhand'
  
  ln = [[sin(x), cos(x), x / 2] for x in np.arange(0,9, 0.1)]
  N = len(ln)
  
  ############################### a simple tube( along ln
  t1 = Tube(ln, c="blue", r=0.08)
  
  ############################### vary radius
  rads = [0.3*(cos(6.0*ir/N))**2+0.1 for ir in range(N)]
  t2 = Tube(ln, r=rads, c="tomato", res=24)
  
  ############################### vary color
  cols = [i for i in range(N)]
  cols = makeBands(cols, 5)  # make color bins
  t3 = Tube(ln, r=rads, c=cols, res=24)
  
  ############################### visualize
  plt = Plotter(N=3, axes=dict(textScale=4))
  plt.at(0).show(t1, __doc__)
  plt.at(1).show(t2)
  plt.at(2).show(t3, viewup="z")
  plt.interactive().close()
  