loaing data from a sequence of files, why it failed?

Hi guys, I'm trying to load data from mat files named "test1.mat",...,"test100.mat". In file "testii.mat", vector Tn has positive values from row (ii-1)*10+1 to row ii*10 and is filled with zeros for any rows before row (ii-1)*10+1. The length of Tn is 10*ii. I wanna store all these positive values of Tn from the 100 mat files in a single vector named allTn. I used the following loop:

clear;
narray=100;
for ii=1:narray
is=num2str(ii);
 name=strcat('test',is);

load(name);

   allTn(((ii-1)*10+1:ii*10)',1)=Tn(((ii-1)*10+1:ii*10)',1); 
    
  
end

However, I got error message "Index in position 1 exceeds array bounds (must not exceed 10)" in the line

   allTn(((ii-1)*10+1:ii*10)',1)=Tn(((ii-1)*10+1:ii*10)',1); 

I also found that the problem is caused by the fact that the loop index is already equal to 3, but name still equals to 'test1'. This causes the problem as I will be citing elements in Tn that do not exist.

I'm wondering why do I got this message, and how should I fix it? In particular, why name is not updated during the loop?

Thanks!

[Rik]

You should load to a struct. Then you can try to narrow down which file is actually causing issue.

Why not load to a struct array and do the processing then?

[Image Analyst]

Evidently allTn only has 10 elements. So why are you trying to go up to 100? Why should the array size in your mat file have the same number of rows as the number of mat files you have? Why is there any relation at all between those?

And that's not good code for looping over files. See the FAQ:

https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

[Tmat]

@Rik Hi Rik. Thanks for the comment. How to load to a struct array?

[Tmat]

@Image Analyst Thanks for the comment. allTn is an array whose size changes in the loop, for example, when ii=1, row 1 to row 10 is filled, and when ii=2, row 11 to row 20 is filled, and so on. The reason I have to do this is that the 100 mat files are generated by a parallell computing device with 100 nodes. For the final analysis, I need to combine them together in a single array. Do you have any suggestions on how to make the code work for my case?

[Walter Roberson]

   allTn(((ii-1)*10+1:ii*10)',1) = Tn;

[Tmat]

@Walter Roberson Thank you very much! I found my problem, that is there is another variable in my test1.mat file named ii, which equals 3. After fixing this, my code could run.

[Stephen23]

@Tmat: that is one of the reasons why it is strongly recommended to load into an output (a scalar structure):

S = load(..);

Benefits for you: much more robust code, less wasted time.

More reasons for avoiding loading directly into the workspace: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval