Matlab | Matlab从入门到放弃(6)

博主github:https://github.com/MichaelBeechan
博主CSDN:https://blog.csdn.net/u011344545
代码下载:https://github.com/MichaelBeechan/Matlab-From-Zero-To-One

%% Time:2019.5.26
%% Function:数组类型

%% 多维数组
R = randn(3,4,5);
% 生成 4! = 24 置换1:4。第 k 个置换为行向量 p(k,:)
p = perms(1:4);    % 排列组合

A = magic(4);
M = zeros(4, 4, 24);

for k = 1 : 24
    M(:, :, k) = A(:, p(k, :));
end

size(M);

% 通过改变第 d 个下标来计算总和
%sum(M, d)
S1 = sum(M, 1);  %1×4×24 
S2 = sum(M, 2);  %4×1×24
S3 = sum(M, 3);  %4×4×1

M = ones(2, 2, 4);

S4 = sum(M, 3)

sum(M, 3)解释:
对于M是一个多维矩阵的情况
此处3可理解为RGB图像的R、G、B分量
求Sum则只是将对应的分量相加即可,即R+G+B
如:
M = ones(2, 2, 4)
S4 = sum(M, 3)

M(:,:,1) =
     1     1
     1     1

M(:,:,2) =
     1     1
     1     1

M(:,:,3) =
     1     1
     1     1

M(:,:,4) =
     1     1
     1     1

S4 =
     4     4
     4     4
上一篇:Scala值类型和String类型转换


下一篇:SAP S4HANA精华帖集锦