import torch
def mutation(self):
'''
mutation of 0/1 type chromosome
faster than `self.Chrom = (mask + self.Chrom) % 2`
:param self:
:return:
'''
mask = (torch.rand(size=(self.size_pop, self.len_chrom), device=self.device) < self.prob_mut).type(torch.int8)
self.Chrom ^= mask
return self.Chrom