如何从矩阵中删除行

Question

我有一个形状为（25,10）的矩阵，也可以是25以外的任何其他数字。我想删除多余的行并得到形状为（20,10）的矩阵

Answer 1

# Let's say your matrix is stored in a variable called "my_matrix"
# then you can do something like this:

my_matrix = my_matrix[:20] # equals to: my_matrix[0:20]

# or:

my_matrix = my_matrix[2:22]

# or if you are using numpy:

indices_to_keep = np.asarray([...indices of elements you want to keep...])
my_matrix = my_matrix[indices_to_keep]