Question

我将稀疏矩阵的非零值存储在字典中。我如何将其转换为实际矩阵？

def sparse_matrix(density,order):
    import random
    matrix = {}
    for i in range(density):
        matrix[(random.randint(0,order-1),
        random.randint(0,order-1))] = 1
    return matrix

Answer 1

选项1： 您可以直接创建矩阵并更新其中的值，而不是将值保留在列表中并稍后创建矩阵。请注意，非零值的数量可以少于“ order”，因为randint可以再次返回相同的数字。

示例代码

import random
import numpy as np
def sparse_matrix(density,order):
    #matrix = [ [0 for i in range(order)] for i in range(order)]
    matrix = np.zeros((order,order))
    for i in range(density):
        matrix[(random.randint(0,order-1))][random.randint(0,order-1)] = 1
    return matrix

输出：

sparse_matrix(2,4)

array([[0., 0., 0., 0.],
       [0., 0., 0., 0.],
       [0., 0., 0., 0.],
       [0., 0., 0., 1.]])

选项2

您可以使用代码创建字典，然后使用该字典更新矩阵中的值。

    def sparse_matrix(density,order):
        import random
        #matrix = [ [0 for i in range(order)] for i in range(order)]
        matrix = {}
        for i in range(density):
            matrix[(random.randint(0,order-1)),(random.randint(0,order-1))] = 1
        return matrix
   #matrix of size order*order
   final_matrix = np.zeros((4,4))

   for key, value in sparse_matrix(2,4).items() :
       final_matrix[key] = value

如何将元组坐标键字典转换为稀疏矩阵

1 个答案: