Equations tags

To flag the portfolio equation in the modfile

[key='value',key='value',...] y = y + 1;

One may want to attach values of any type to an equation. Currently, only strings of characters are recognized but we ask the user to specify users to enter quoted strings nevertheless. Type of keys should also be restricted so that they can be used as fields in matlab structures if needed, i.e. no numeric character, no space,...

M_.equations_tags = {
    1 'name' 'First equation';
    2 'name' 'Second equation';
    2 'portfolio' 'true';
};

tags = M_.equations_tags;
tags(cell2mat(tags(:,1))==2,2:3) % all tags for equation 2
tags(strmatch('name',tags(:,2)),[1 3]) % a vector with equations numbers and associated names