将3D矩阵与2D矩阵相乘 [英] Multiply a 3D matrix with a 2D matrix

问题描述

假设我有一个 AxBxC 矩阵X和一个 BxD 矩阵Y.

Suppose I have an AxBxC matrix X and a BxD matrix Y.

是否存在一种非循环方法，我可以通过该方法将每个 C AxB 矩阵与Y相乘?

Is there a non-loop method by which I can multiply each of the C AxB matrices with Y?

推荐答案

您可以使用

You can do this in one line using the functions NUM2CELL to break the matrix X into a cell array and CELLFUN to operate across the cells:

Z = cellfun(@(x) x*Y,num2cell(X,[1 2]),'UniformOutput',false);

结果Z是一个 1-by-C 单元格数组，其中每个单元格都包含一个 A-by-D 矩阵.如果希望Z成为 A-D-D-C 矩阵，则可以使用

The result Z is a 1-by-C cell array where each cell contains an A-by-D matrix. If you want Z to be an A-by-D-by-C matrix, you can use the CAT function:

Z = cat(3,Z{:});

注意::我的旧解决方案使用了 MAT2CELL 而不是 NUM2CELL ，不那么简洁:

NOTE: My old solution used MAT2CELL instead of NUM2CELL, which wasn't as succinct:

[A,B,C] = size(X);
Z = cellfun(@(x) x*Y,mat2cell(X,A,B,ones(1,C)),'UniformOutput',false);

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