CODE EXAMPLE FOR PYTHON

replace matrix values python

>>> import numpy as np
   >>> M = np.arange(10)
   >>> M
   array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
   >>> M[(M > 2) & (M < 7)] = -1
   >>> M
   array([ 0,  1,  2, -1, -1, -1, -1,  7,  8,  9])