Question

我之前从未使用过MATLAB，但我必须做一个处理25（行）x 25（col）矩阵的操作。所以我不想手工做到这一点。所以我必须使用matlab。

我想在GF（2）的MATLAB中定义矩阵（2阶的Galois域是一个称为字段的数学结构，提供算术模2的正式定义。）

以下是我的5x5矩阵，我从命令null获取空格（MATRIX，'r'）

1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
0   0   0   1   1   0   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
1   0   0   0   0   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   
0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   0   
0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   
0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   
0   0   0   0   1   0   0   0   1   1   0   0   0   0   1   0   0   0   0   0   0   0   0   0   0   
0   0   0   0   0   1   0   0   0   0   1   1   0   0   0   1   0   0   0   0   0   0   0   0   0   
0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   0   
0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   0   
0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   0   0   0   
0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   0   0   0   0   1   0   0   0   0   0   
0   0   0   0   0   0   0   0   0   0   1   0   0   0   0   1   1   0   0   0   1   0   0   0   0   
0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   0   
0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   0   
0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   0   1   0   
0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   0   0   0   0   1   
0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   0   1   1   0   0   0   
0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   0   
0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   0   
0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1   1   
0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1   1

以下是我的6x6矩阵，当我尝试命令null（MATRIX，'r'）时，我得到空结果

1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 0 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1

任何人都可以告诉我是什么原因吗？

Answer 1

由于矩阵的所有元素都是这样写的，只需写A=[然后复制矩阵，然后放];。例如，如果矩阵是

1 2 3
4 5 6
7 8 9

然后你可以做

A=[1 2 3
   4 5 6
   7 8 9];

然后找到使用null(A)的空格。

Answer 2

对于第二部分，你能在matlab中使用函数“null”吗？ http://www.mathworks.com/help/matlab/ref/null.html

对于第一部分，也许这会有所帮助：Learning to build band matrices in MATLAB

你正在尝试制作带状矩阵，对角线上的带子也会增加5，然后减少5。为了制作这些，我认为你可以做到

[m,n] = size(A);
i = 1;
for j = 6:n
    A(i,j) = 1;
    i = i+1;
end

这将产生上对角线。要做到更低，只需做

j = 1;
for i = 6:n
    A(i,j) = 1;
    j = j+1;
end

Answer 3

构造这种带状矩阵的更简单方法是

A = toeplitz（[1 1 0 0 0 0 1 0（1,18）]）

我的经验法则：每个for循环都无法有效地使用Matlab。

在GF（2）的MATLAB中定义矩阵

3 个答案: