Update ica.py

ica.py

@@ -35,6 +35,7 @@ def ica(x, **args):
     '''training loop using graident descent'''
     for step in range(nsteps):
         # ***insert gradient descent code here***
+        ''' use backtracking line search '''
         
         # print loss
         print('step: {} / {}, L: {}'.format(step, nsteps, L[step]))