Index exceeds Matrix dimensions

Question

Mridul Garg 2016-7-7

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/294239-index-exceeds-matrix-dimensions

评论： Star Strider 2016-7-8

Hello

I am trying to run the following block of code-

    for q = patient_num(1):patient_num(end)
        flag=[];
        i=0;
        num = num2str(patient_num(q));
        for j= file_num(1):file_num(end)
        file = num2str(file_num(j));
        record_file = strcat('explained','_','ch','_',num,'_',file,'-percent-explain-10', '.mat');
        cd ('/scratch/group/eegnw/EEG/DATA/')
        flag[i]=load('-mat',record_file);
        i=i+1;
        end
    end

I want to check if this is running correctly or not by looking at the value of i at the end. I give inputs as patient_num=1:3, file_num=2:4. However, after running the outer loop for one patient_num, I get an error saying Index exceeds matrix dimensions. Basically the value of patient_num has changed from a vector [1 2 3] to just a scalar 1. I can't figure out why that is happening as my code doesn't modify that anywhere. Any help is appreciated.

Expected output- i=9

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

Walter Roberson 2016-7-7

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/294239-index-exceeds-matrix-dimensions#answer_228048

Using that form of load() is not recommended. It is recommended that instead you assign the output of load() to a variable. The result will be a structure with one field for each variable stored in the file. You then extract the needed parts of the structure. This approach cannot accidentally overwrite unexpected variables like your current approach can.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Mridul Garg 2016-7-7

I tried that, introducing a variable names flag=[], and storing the output of load in it. Still the same error

请先登录，再进行评论。

Answer 2

James Tursa 2016-7-7

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/294239-index-exceeds-matrix-dimensions#answer_228042

Is there a variable named patient_num in the mat file?

6 个评论
显示 4更早的评论隐藏 4更早的评论

James Tursa 2016-7-7

编辑：James Tursa 2016-7-7

Please show your current code. Are you sure that patient_num is the expected vector at the start of this code? What happens if you comment out the load command and then run this section of code?

Mridul Garg 2016-7-8

在 MATLAB Online 中打开

I updated the code but it gives me another error now-

Error: Unbalanced or unexpected parenthesis or bracket.

请先登录，再进行评论。

Answer 3

Star Strider 2016-7-8

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/294239-index-exceeds-matrix-dimensions#answer_228080

在 MATLAB Online 中打开

The square bracket here is not legal MATLAB syntax:

flag[i]=load('-mat',record_file);

consider instead:

flag{i} = load('-mat',record_file);

4 个评论
显示 2更早的评论隐藏 2更早的评论

Walter Roberson 2016-7-8

Star Strider, is it part of the debugging that you do not load() the file?

Star Strider 2016-7-8

Here, yes. The indexing seems to be the problem, so sorting that first may be appropriate.

Also, there are no files to load. I would create one or more, but I have no idea what they actually contain, so I can’t simulate what the code does. I don’t understand where the matrix dimensions problem arises (other than initialising ‘i’ in the inner loop and expecting it to eventually equal the sum of iterations of the inner and outer loops, since it will currently count only to whatever the inner loop limit is).

请先登录，再进行评论。