Prevent overwriting within a for loop in 3D-motion tracking

Hi all,

a analyse 3-D motion data in humans. I want to import multiple .xlsx files at once and save the output in one table. So far, in my for loop matlab overwrites the data so that I have only the results in my table with the last iteration (n=21).

Next steps after save all files in one table are to select relevant data and calculate maximum and mean data.

I tried a lot but can't find a solution.

Regards and thank you very much for yout help.

clc; clearvars; close all

data = dir ("*.xlsx") ;
N = length (data) ;
for i =  1:N   
    thisFile = data(i).name;
    T  = readtable (thisFile);
end

[Sean Brennan]

In the line:

T  = readtable (thisFile);

This command overwrites the prior T value. An easy fix for this is to index the variable, one for each table: For example:

T(i) = readtable (thisFile);

In subsequent processing, you can then again do a loop over the tables to generate the analysis for each. For example:

for ith_table = 1:length(T)
  % Do your analysis on each table here, where each table can be recovered
  % as T(ith_table)
end

[Jonas Bender]

Dear Sean,

I tried indexing before. Matlab said: "Subscripting into a table using one subscript (as in (t (i)) is not supported. ...

It may be a problem that "thisFile" is a char?

Regards, Jonas

T(i) = readtable (thisFile);

Answer 1

[Peter Perkins]

You may just want

T = table();
for ...
    ...
    T  = [T; readtable (thisFile)];

[Jonas Bender]

Dear Peter,

this looks like a quite good solution. creating an empty table and fill this table. However, when I tried yout code an error message occured:

Error using readtable. Not enough input arguments.

Do you have an explanation?

Jonas

[Peter Perkins]

I do: remove the space that I unintentionally put between "readtable" and (thisFile). Oops! Sorry about that!