How to create indices for the k-fold cross-validation?

Question

Susan 2021-6-8

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/851105-how-to-create-indices-for-the-k-fold-cross-validation

评论： Susan 2021-6-10

采纳的回答： Megumi Fukuda

在 MATLAB Online 中打开

Hi All,

I'd like to create indices for the k-fold cross-validation using

indices = crossvalind('Kfold',Labels,k);

The "Labels" is a 1-by-1000 cell array which contains 1000 cells, as follows

  Labels(1: 10) = 1×10 cell array
  Columns 1 through 9
    {1×1 cell}    {1×1 cell}    {1×1 cell}    {1×1 cell}    {1×1 cell}    {1×1 cell}    {1×1 cell}    {1×1 cell}    {1×1 cell}
  Column 10
    {1×1 cell}
    
    
    
    Labels{1}= 1×1 cell array
    {'2'}

I got this error

Undefined function 'crossvalind' for input arguments of type 'cell'.

So, I took the following steps to solve the issue

Label_1 = cellfun(@(x) str2double(x), Labels, 'UniformOutput',false);
Label_double = [Label_1{:}]
indices = crossvalind('Kfold',Label_double,10);

And now I am dealing with the following error

Undefined function 'crossvalind' for input arguments of type 'char'.

I'm not sure why I get this error. any idea? Thanks!

3 个评论
显示 1更早的评论隐藏 1更早的评论

Megumi Fukuda 2021-6-9

Could you upload your label variable (you can upload .mat file) so that I can have a look? I assume your label is what-I-call 'nested' and that's why you cannot use crossvalind.

Susan 2021-6-9

编辑：Susan 2021-6-9

Label.mat

@Megumi Fukuda Sure thing! The label is attached.Thank you so much in advance for your help.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Megumi Fukuda 2021-6-10

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/851105-how-to-create-indices-for-the-k-fold-cross-validation#answer_721440

在 MATLAB Online 中打开

indices = crossvalind('Kfold',Labels,k);

I am sure this does not work, as the cells in the variable Label are nested and cannot be used for crossvalind without converting the variables.

I have tested this code with MATLAB 2021a and this code looks fine. Would you like to try your code again?

% clear the workspace
load('Label.mat'); % the mat file you uploaded
Label_1 = cellfun(@(x) str2double(x), Giant_bpm, 'UniformOutput',false);
Label_double = [Label_1{:}];
indices = crossvalind('Kfold',Label_double,10);

(... and here is another implementation I came up with. This returns the label as char type)

load('Label.mat');
Giant_bpm_updated = cellfun(@cell2mat, Giant_bpm(:), 'UniformOutput', false);
indices = crossvalind('Kfold',Giant_bpm_updated,10);

Hope this helps!

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Susan 2021-6-10

Thanks for your response.

Interesting! when I run my code I get the same error as before but your code works fine.

请先登录，再进行评论。

How to create indices for the k-fold cross-validation?

3 个评论
显示 1更早的评论隐藏 1更早的评论

采纳的回答

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

How to create indices for the k-fold cross-validation?

3 个评论 显示 1更早的评论隐藏 1更早的评论

采纳的回答

1 个评论 显示 -1更早的评论隐藏 -1更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

3 个评论
显示 1更早的评论隐藏 1更早的评论

1 个评论
显示 -1更早的评论隐藏 -1更早的评论