在Matlab中从矩阵中删除行和列

问题描述：

我们应该如何有效地从Matlab中的矩阵中删除多行和多列? 向量包含应删除的索引.

How should we efficiently remove multiple line and columns from a matrix in Matlab? A vector holds indices that should be removed.

输入:t乘t矩阵

输出:(t-k)x(t-k)矩阵，其中k个不相邻的行和相应的列从输入矩阵中删除.

Output: (t-k) by (t-k) matrix in which k non-adjacent rows and corresponding columns are removed from input matrix.

答

这应该可以解决您的问题.

This should solve your problem.

matrix=randi(100,[50 50]);
rows2remove=[2 4 46 50 1];
cols2remove=[1 2 5 8 49];
matrix(rows2remove,:)=[];
matrix(:,cols2remove)=[];

第二个想法，如果您有索引，则首先使用功能ind2sub将这些索引转换为下标:

On the second thought, if you have indices, then first convert those indices to subscripts by using the function ind2sub as:

[rows2remove,cols2remove] = ind2sub(size(matrix),VecOfIndices);

现在，您将获得需要删除的元素的行索引和列索引.不能从矩阵中删除单个元素.因此，我假设您需要删除整个列和行.可以这样完成:

Now you will get row and column indices of elements which need to be removed. Individual elements cannot be removed from a matrix. So I am assuming that you need to remove the entire column and row. That can be done as:

rows2remove=unique(rows2remove);
cols2remove=unique(cols2remove); 
matrix(rows2remove,:)=[];
matrix(:,cols2remove)=[];

如果要删除单个元素，请使用单元格数组或将这些元素替换为一些过时的值，例如9999.

If you want to remove individual elements then either use a cell array or replace those elements with some obsolete value such as 9999.

在Matlab中从矩阵中删除行和列

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