change the dimension of a cell in a cell array

Question

ZEMIN HUANG 2021-1-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/727558-change-the-dimension-of-a-cell-in-a-cell-array

评论： Image Analyst 2021-1-31

hi, i have a cell array of size 480000x1, in each cell, the size is 384x1 as shown in the picture. I would like to change the 384x1 dimension of every cell to 6x64. could anyone help me please? thanks in advance.

i tried writing the below code but got an error. help please!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

David Hill 2021-1-26

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/727558-change-the-dimension-of-a-cell-in-a-cell-array#answer_606738

在 MATLAB Online 中打开

for k=1:length(XTrain)
    XTrain{k}=reshape(XTrain{k},6,[]);
end

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

ZEMIN HUANG 2021-1-26

THANKS DAVID! THATS HELPFUL

请先登录，再进行评论。

Answer 2

Image Analyst 2021-1-26

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/727558-change-the-dimension-of-a-cell-in-a-cell-array#answer_606743

You almost definitely should not use a cell array for this. They are slow and have lots of overhead. It looks like you can use a regular double 480000 x 384 matrix, or even a table. Just start out with a 3-D array of 480000 x 6 x 64.

3 个评论
显示 1更早的评论隐藏 1更早的评论

ZEMIN HUANG 2021-1-31

hi image analyst, how do i convert the cell array to 480000x384 matrix that you mentioned

Image Analyst 2021-1-31

在 MATLAB Online 中打开

You would not convert it because you would/should never create a cell array in the first place. You would just do

    for row = 1 : 48000
        for k = 1 : 64
            column1 = (k-1) * 6 + 1;
            column2 = column1 + 5;
            m(row, column1 : column2) = someVectorOfLength6;
        end        
    end