Need help about calling m file into Matlab command window/workspace ...

     My version of the matlab is r2010b!

     I have 2 m-files, the main one - it first runs in a command window (main.m), and the other one (data.m), which is called during  the execution of the first - for loading data ...

    main.m
      %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      clear
      clc
      while 1
         edit ('data.m')
         disp ('After the completion of data entry, press 1,');
         disp ('To change the input data, press 0');
         k = input ('');
         if (k == 1)
            fprintf ('\ n Loading data ..... \ n \ n')
            data
            break;
         end
      end
      s = a * 10
      %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

      data.m
      %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      clear
      a = [1 2 3 4 5]
      %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

      First I run main.m --- it opens data.m --- I change vector a (eg a = [10 20 30]) --- and save it (click on the save button) --- BUT INSTEAD OF LOADING NEW-Changed vector a = [10 20 30], main.m loads the previous one (a=[1 2 3 4 5] ) from data.m !!!!!
      Only when I restart main.m then it loads a changed vector --- [10 20 30 ]................

      How do I fix this? tnx

Nikola

[Oleg Komarov]

Any particular reason why you're storing data in an .m file?

Answer 1

[nikola]

rehash solves it!!! tnx to Walter Roberson and others ;)

main.m

          clear
          clc
          while 1
             edit ('data.m')
             disp ('After the completion of data entry, press 1,');
             disp ('To change the input data, press 0');
             k = input ('');
             if (k == 1)
                fprintf ('Loading data...')
                rehash %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
                data
                break;
             end
          end
          s = a * 10

Answer 2

[Fangjun Jiang]

Add a line pause(0) after the line edit('data.m') in main.m and it should work.

It forces MATLAB to refresh file/folder so the updated data.m is reflected.

[Walter Roberson]

pause() and drawnow() do *not* do rehash() !

[nikola]

but it seems that "rehash" does.....

[Fangjun Jiang]

Something strange. Yesterday when I tried, I saw the problem which was the updated data.m didn't take effect. I added pause(0) which did make a difference. Today, when I tried, your original code worked. Without pause(0), the updated data.m did take effect. So what is your verdict? I'll find out more.

Answer 3

[Oleg Komarov]

In main.m:

...
s = a * 10
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
data.m
...

but then you clear and you declare a independently on what's stored in data.m:

...
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
clear
a = [1 2 3 4 5]
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

So, it did load the modified a but you cleared it and then created the old one.

Apart from this what are you trying to accomplish? The approach may be not the best one.

EDIT

Keeping your inputs separate from the script has sense only if the amount of data is relevant and even in this case .mat files are more suitable for this task.

Even if you have 30 variables, but they are compact/short, it would make sense to keep them all in a separate section but on the same .m file.

For this purpose use cell mode:

%%INPUTS

a = 1:5;
b = ...
z = ...

%%ENGINE

Or, if the user has to be continuosly prompted for inputs you could use input directly or inputdlg with default answer so that the user could accept or edit the default.

Your solution is not robust because it's enough to forget to save once that you have to repeat the editing process from the beginning.

[Fangjun Jiang]

That might be the OP's debugging code. When I tried it I didn't include it. I think I understand his issue. It is the updated data.m not being used when main.m continues execution. Add a pause(0) or drawnow could solve the problem. But I agree this is probably not the best approach to the OP's task.

[nikola]

"It is the updated data.m not being used when main.m continues execution." -----exactly, but pause(0) or drawnow is not fixing it!

By the way, this is my first matlab project - it's about mechanical calculations...

I use data.m for user to input various data, for example it looks like:

...

% type value for maximum working stress [daN/mm2]:

m=10;

% type value for specific weight additional load [daN / mm 2 * m]:

n=2.5;

...

Around 20 different vectors and matrix have to be inputed. After that, they are use in main.m for later calculation.

This is the way I organized my matlab project...if you have any suggestion feel free to write. tnx

Nikola

[Oleg Komarov]

What I do is:

1) in the command window: main.m

2) data.m is prompted, I edit a

3) I save data.m

4) in the command windonw: 1

a,s,k appear in the workspace all according to the modified values of a I edited in point 2.

Again, what clear is there for after you executed main.m?

And why do you redeclare a?

If this is not your problem, then take the time to show what are you really doing?

Also, see my edit for an alternative to manage your project.

Answer 4

[Fangjun Jiang]

I did the following test. The problem is clear. The updated data.m file didn't take effect. With or without pause(0) didn't make a difference. I must have made some mistakes.

rehash() is the right function to use. But it needs to be put after the "k=input(' ') line.

data.m contains one line: a=1

main.m

clear
  while 1
     edit ('data.m')
     pause(0);
     disp ('After the completion of data entry, press 1,');
     disp ('To change the input data, press 0');
     k = input ('');
     if (k == 1)
        fprintf ('\n Loading data ..... \n')
        data
        break;
     end
  end
  s = a * 10

Run the following code. Every time data.m is brought up, edit it with the same value as Iteration (1,2,3) and save it.

diary('out.txt');
for Iteration=1:3
    fprintf('Iteration=%d\n',Iteration);
    main;
end
diary off;

out.txt

Iteration=1
After the completion of data entry, press 1,
To change the input data, press 0
1

   Loading data ..... 

a =

       1

s =

      10

Iteration=2
After the completion of data entry, press 1,
To change the input data, press 0
1

   Loading data ..... 

a =

       1

s =

      10

Iteration=3
After the completion of data entry, press 1,
To change the input data, press 0
1

   Loading data ..... 

a =

       1

s =

      10

[Oleg Komarov]

Ok, I see the problem. In my case only the first modification is correctly taken into account BUT

I would not recommend to follow this road as I already pointed out in my EDIT.

This way of storing data and retrieving is "unnatural" and shows this unexpected behaviour, which may or may not be a bug.