将矩阵添加到列表

Question

我有这段代码可以生成一些随机矩阵：

for i in range(5):
c = randint(1,10)
r = randint(1,10)
(Matrix(QQ,[[randint(-5,5) for x in range(c)] for y in range(r)]))

我的问题是如何将这些矩阵添加到列表中？谢谢。

Answer 1

可以将事物添加到列表中使用列表的 append 和 extend 方法。

示例：创建一个空列表并追加矩阵在构建它们时使用它。

matrices = []

for _ in range(5):
    c = randint(1, 10)
    r = randint(1, 10)
    m = Matrix(QQ, [[randint(-5, 5) for _ in range(c)] for _ in range(r)]))
    matrices.append(m)

要直接构建列表，请使用 Python 的理解语法：

matrices = [
    Matrix(QQ, [[randint(-5, 5) for _ in range(randint(1, 10))]
                for _ in range(randint(1, 10))]))
    for _ in range(5)
]

可以定义一个随机矩阵函数，并用它来构建矩阵列表。

def my_random_matrix(emax=5, rmax=10, cmax=10):
    r"""
    Return a random matrix of random size.

    The number of rows is picked at random between ``1`` and ``rmax``.
    The number of columns is picked at random between ``1`` and ``cmax``.
    The entries are integers picked at random between ``-emax`` and ``emax``.
    The matrix is returned as a matrix over ``QQ``.
    """
    r, c = randint(1, rmax), randint(1, cmax)
    return Matrix(QQ, r, c, [randint(-emax, emax) for _ in range(r * c)])

matrices = [my_random_matrix() for _ in range(5)]

将矩阵添加到列表

Add matrices to a list

python

matrix

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