Divide matrix in subgroups

5 次查看（过去 30 天）

Fercho_Sala 2021-4-15

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/803001-divide-matrix-in-subgroups

评论： Star Strider 2021-4-22

Hello everyone, just a simple question : having a matrix X ,how can I divide the total number of columns in 24 subgroups and each subgroup give a number as variable name? Thanks.

采纳的回答

Star Strider 2021-4-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/803001-divide-matrix-in-subgroups#answer_675961

The mat2cell function will likely do what you want.

Note that assigning each matrix to a different variable is not advisable. Keep them as the cell array, and refer to them as elements of it, using subscripts.

Dividing a (9x9) matrix into 9 (3x3) matrices would work as:

A = randi(9, 9);
Adiv = mat2cell(A, [1 1 1]*3, [1 1 1]*3);

14 个评论
显示 12更早的评论隐藏 12更早的评论

Star Strider 2021-4-21

Try this:

L1 = load('R.mat');
L2 = load('t.mat');
L3 = load('y.mat');
R = L1.A;
t = L2.A;
tdn = datevec(t);                                       % Date Vectors
MinutesGroup = 30;                                      % Number Of Minutes In Each Group
group = rem(tdn(:,5), MinutesGroup)==0;                 % Grouping Variable ‘Steps’
[Ut,ia,idx] = unique(cumsum(+group));                   % Unique Groups
Counts = accumarray(idx, 1);                            % Items In Each Group
C = mat2cell(R, size(R,1), Counts);                     % Cell Array Of Partitioned ‘R’ Matrix By ‘Groups’ Vector

It took a few minutes to figure out how to do this, and make it as robust as possible. This should allow any integer value of ‘MinutesGroup’ between 1 and numel(t) to define the partitions. (I checked it a number of different values for ‘MinutesGroup’ using the time vector as datevec rows, and it partitions everything correctly, at least with the data set provided.)

It might be possible to do a similar analysis with retime, however you requested a way to partition the data, not analyse it, and this code does exactly that.

Fercho_Sala 2021-4-22