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Altair Compose - Hold data from readcae for loop

Hi everybody,

It's been a while I'm struggling with a for loop involving readcae command on compose.

I've got a .op2 result file and I need to get element stresses for a set of elements and for different loadcases. Specifically, I have 4 elements and 2 loadcase.

Following the scripts I'm using (X is the op2 filename):

Elements = {'E1','E2','E3','E4'};
Subcase_List=getsubcaselist(X)
Subcases=numel(Subcase_List)

for i=1:Subcases
E_=readcae(X,Subcase_List{i},'Stress (2D)',Elements,{'XX (Z1)','YY (Z1)','XY (Z1)','vonMises (Z1)','XX (Z2)','YY (Z2)','XY (Z2)','vonMises (Z2)'},[],1)
end

At the end of each iteration I get a submatrix with all the requested components ('XX (Z1)','YY (Z1)', etcc…) in columns and elements in rows for each subcase.

I need to store this submatrix for each iteration, hence for each subcases.

Is there a way to get it?

Thanks in advance

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Accepted answers

RSGarciarivas

Hi @Giuseppe Pavano,

If you need all results to be stored in a 2D matrix, that's easy as well. I just thought a different slice for each loadcase would be better :D.

Try this:

close all, clear, clc

E = [];
Nsubcases = 4;
for i = 1:Nsubcases
_E = i*ones(4,8);
E = [E; _E];
end
E

These lines append each segment of the mock data I created as new row in a 2D matrix. Test and substitute for the real readcae call.

Rafael

Giuseppe Pavano

Hi @RSGarciarivas,

I've tried the following (I've simplified parameters called by readcae function):

It works very well!😀

Thank you very much for your advices and replies.

All comments

RSGarciarivas

hi @Giuseppe Pavano,

You could do something like:

E = nan(N_subcases, N_elements, N_components); % Initialize 3D matrix

for i=1:Subcases

E_=readcae(X,Subcase_List{i},'Stress (2D)',Elements,{'XX (Z1)','YY (Z1)','XY (Z1)','vonMises (Z1)','XX (Z2)','YY (Z2)','XY (Z2)','vonMises (Z2)'},[],1)

E(i,:,:) = E_; % Append this subcase as a new entry in the results matrix

end

You might have to use function squeeze after calling readcae to remove redundant dimensions.

Rafael

Giuseppe Pavano

Hi @RSGarciarivas ,

thank you for your reply.

I've tried this:

I have 4 elements and 2 loadcases so the E matrix should be 8 rows and 8 columns. I've created a E matrix with command E=nan(8,8).

In the for loop I've used the command E(i,:,:) = E_; to append the subcase to result matrix.

It didn't work and gave me the following error:

Line number 16 refer to E(i,:,:) = E_ command.

I think there is a problem with the append command.

RSGarciarivas

Hi @Giuseppe Pavano,

In line:

E = nan(N_subcases, N_elements, N_components)

I meant a 3D matrix so the first dimension stores each loadcase separately. In your case, E = nan(2, 4, 8)

Command E(i,:,:) = E_; assigns the current subcase to the ith element of first dimension of the 3D matrix

Rafael

Giuseppe Pavano

HI @RSGarciarivas ,

I've tried your workaround and it seems to be working, no errors. I just really don't know how to manage the results. Let me explain.

My goal is to have a matrix like this:

Subcase Element Component1 Component2…….Component N

I would like this for each element and for each subcase.

The command you gave me works fine but I don't know how to arrange the results in the way I show above.

I there a way to modify my script and get what I need?

Many thanks,

Giuseppe Pavano

Hi,

probably I found the mistake. I modify my script this way:

Elements = {'E1','E2','E3','E4'};
%E=nan(N_subcases, N_elements, N_components); % Initialize 3D matrix
E=nan(4,8,2) ⇒ I made a mistake, I wrote E=nan(8,4,2)
Subcase_List=getsubcaselist(X);
Subcases=numel(Subcase_List);

for i=1:Subcases
E_=readcae(X,Subcase_List{i},'Stress (2D)',Elements,{'XX (Z1)','YY (Z1)','XY (Z1)','vonMises (Z1)','XX (Z2)','YY (Z2)','XY (Z2)','vonMises (Z2)'},[],1)
E(:,:,i) = E_;
end
E

Now it works very close the way I want it would work: Following what I get:

Now, How to rearrange all in a 2D matrix, without slicing?

Thanks

RSGarciarivas

Hi @Giuseppe Pavano,

If you need all results to be stored in a 2D matrix, that's easy as well. I just thought a different slice for each loadcase would be better :D.

Try this:

close all, clear, clc

E = [];
Nsubcases = 4;
for i = 1:Nsubcases
_E = i*ones(4,8);
E = [E; _E];
end
E

These lines append each segment of the mock data I created as new row in a 2D matrix. Test and substitute for the real readcae call.

Rafael

Giuseppe Pavano

Hi @RSGarciarivas,

I've tried the following (I've simplified parameters called by readcae function):

It works very well!😀

Thank you very much for your advices and replies.

RSGarciarivas

Glad it worked, @Giuseppe Pavano! Please mark answer as correct so other users can refer to this.

Reach out if needed!

Rafael