code: def resolve_ambigs(tmpseq):
      
      ## iterate over the bases 'RSKWYM': [82, 83, 75, 87, 89, 77]
      for ambig in np.uint8([82, 83, 75, 87, 89, 77]):
          ## get all site in this ambig
          idx, idy = np.where(tmpseq == ambig)
          ## get the two resolutions of the ambig
          res1, res2 = AMBIGS[ambig.view("S1")]
          ## randomly sample half those sites
          halfmask = np.random.choice([True, False], idx.shape[0])
          ## replace ambig bases with their resolutions
          for i in xrange(halfmask.shape[0]):
              if halfmask[i]:
                  tmpseq[idx[i], idy[i]] = np.array(res1).view(np.uint8)
              else:
                  tmpseq[idx[i], idy[i]] = np.array(res2).view(np.uint8)
      return tmpseq
docs: returns a seq array with 'RSKYWM' randomly replaced with resolved bases