对2D矩阵中的块求和-MATLAB [英] Sum over blocks in a 2D matrix - MATLAB

问题描述

我正在研究Matlab，想知道如何在大型矩阵中添加术语.具体来说，我有一个4914x4914矩阵，并想创建一个189x189矩阵，其中每个项等于每个26x26子集中的项之和.

I'm working on Matlab and was wondering how I add terms within a large matrix. Specifically, I have a 4914x4914 matrix and would like to create a 189x189 matrix, where each term is equal to the sum of the terms in each 26x26 subset.

为说明起见，假设我具有如下神奇的4x4矩阵:

To illustrate, say I had the magic 4x4 matrix as follows:

[16 2  3  13;

 5  11 10 8;

 9  7  6  12;

 4  14 15 1]

，我想创建一个2x2矩阵，该矩阵等于原始魔术4x4中每个2x2矩阵的总和，即:

and I wanted to create a 2x2 matrix equal to the sum of each 2x2 matrix within the original magic 4x4, i.e.:

[(16+2+5+11)   (3+13+10+8);

(9+7+4+14)  (6+12+15+1)]

感谢您的任何建议！ 谢谢 杰克

Grateful for any advice! Thanks jake

推荐答案

另一种方法是将整个矩阵重塑为4D矩阵并将第一维和第三维上的元素求和:

An alternative way is to reshape the whole matrix into a 4D matrix and sum the elements over first and third dimension:

result = squeeze(sum(sum(reshape(A,26,189,26,189),1),3));

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