Split a matrix at specific row

12 次查看（过去 30 天）
Alex Grimaud
Alex Grimaud 2018-3-6
回答： Alex Grimaud 2018-3-12
Hello,
I have a 105x4 matrix and a vector [11 12 11 11 12 12 13 11 12] where the sum represent the row size of the matrix. I want to divide the matrix into several matrix, the first will start at row 1 to 11 and give a 11x4 matrix. The second will start a 12 to 24 and give a 12x4 matrix.. etc.. How can i do that? i'm a little bit lost
Thanks in advance for your help

请先登录，再回答此问题。

采纳的回答

Jos (10584)
Jos (10584) 2018-3-12
Use mat2cell:
M = randi(20, 105,4) ;
V = [11 12 11 11 12 12 13 11 12] ;
C = mat2cell(M, V , size(M,2)) ;

更多回答（2 个）

Akira Agata
Akira Agata 2018-3-12
Like this?
% Input matrix (A) and vector (h)
A = rand(105,4);
h = [11 12 11 11 12 12 13 11 12];
% Calculate start- and end-row index based on the given vector
endIdx = cumsum(h);
startIdx = [1 endIdx(1:end-1)+1];
% Separate the matrix
C = arrayfun(@(x,y) A(x:y,:),startIdx,endIdx,'UniformOutput',false);
The result looks like:
>> C
C =
1×9 cell array
{11×4 double} {12×4 double} {11×4 double} {11×4 double} {12×4 double} {12×4 double} {13×4 double} {11×4 double} {12×4 double}
  2 个评论
Jos (10584)
Jos (10584) 2018-3-12
Why so difficult? More than a decade ago, Matlab has created the function mat2cell to do exactly this ...
Akira Agata
Akira Agata 2018-3-12
编辑：Akira Agata 2018-3-12
Yes, mat2cell has just slipped my mind. Thanks!

请先登录，再进行评论。

Alex Grimaud
Alex Grimaud 2018-3-12
Thanks for the reply, the two solution works perfectly. But mat2cell is more simple !

类别

在 Help Center 和 File Exchange 中查找有关 Operators and Elementary Operations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by