Numpy thermometer encoding

Question

I am trying to use numpy optimized in-built functions to generate thermometer encoding. Thermometer encoding is basically generating n amount if 1\'s in a given len

Answer 1

Wim's answer is incredible. I also never heard of thermometer encoding, but if I were to do I would go with map. It's simply shorter without for loop solution. The performance is quite similar.

>>> def setValue(val):
      return np.append(np.ones(val), np.zeros(8-val))
>>> np.array(list(map(setValue, [2,3,4,5])))

array([[ 1.,  1.,  0.,  0.,  0.,  0.,  0.,  0.],
   [ 1.,  1.,  1.,  0.,  0.,  0.,  0.,  0.],
   [ 1.,  1.,  1.,  1.,  0.,  0.,  0.,  0.],
   [ 1.,  1.,  1.,  1.,  1.,  0.,  0.,  0.]])

or one-liner with lambda function

>>> np.array(list(map(lambda v: np.append(np.ones(v), np.zeros(8-v)), [1,6,3,8])))

array([[ 1.,  0.,  0.,  0.,  0.,  0.,  0.,  0.],
   [ 1.,  1.,  1.,  1.,  1.,  1.,  0.,  0.],
   [ 1.,  1.,  1.,  0.,  0.,  0.,  0.,  0.],
   [ 1.,  1.,  1.,  1.,  1.,  1.,  1.,  1.]])