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Let's use the information gleaned from this page to create our structure using the struct function. The help says that the format for using the struct function is

strArray = struct('field1',val1,'field2',val2, ...)

Bring up the editor by clicking on the New M-file icon (or any other preferred way). Copy the above struct statement into the M-file and modify it to create the sigepstruct structure.

sigepsstruct = struct('eps', eps_val, ...
                     'sig', sig_val);

We use "..." to start a new line. In order for this to work, we, of course, need to allocate strain and stress values to eps_val and sig_val, respectively, abovethis statement. We'll use dummy values that would horrify any self-respecting solid mechanics professor. We do so in order to make the programming aspects easier to understand.

_{{%Testing the use of structure_}}
_{{clear all; %Clear all variables from workspace_}}
_{{eps_val = \[2 7 4\];%Nonsense   values_}}
_{{R = 2*eye(3); %Dummy R_}}
_{{sig_val = (R*eps_val')';%Derived nonsense_}}

In your actual redAnTS implementation, the strains will be derived from the displacements that redAnTS provides from inversion of the stiffness matrix. And you'd have a meaningful R matrix. Note that we specify eps_val as a row vector; we have to use the transpose operator (') to ensure we end up with a row vector for sig_val also.

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We have now created our structure. Let's now see how we can extract parts of the structure. Since you are a real woman/man, go back to the above help page and read the section on Accessing Data in Structure Arrays. It tells you that to access a field of a particular structure, include a period (.) after the structure name followed by the field name. Use this to extract the entire stress vector and, say, the second item in the eps field (which is ε_yy).

%Extract data from structure
sigepsstruct.sig %Extract the stress vector
sigepsstruct.eps(2)%Extract the 2nd element of eps

Check in the command window that the correct values are extracted.

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