<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">Dear Sir/Madam, </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">Thank you for developing such a great library. I am currently learning how to use it. I have a question as follows. Could you give me some suggestions? </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">The question is as follows. </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">Given a NNC_Polyhedron, I want to merge two dimensions in it, say dim1 and dim2. Then, my current code is </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><font face="arial, helvetica, sans-serif">_polyhedron.add_constraint(PPL::Variable(dim1) == PPL::Variable(dim2));<br></font><span style="font-family:arial,helvetica,sans-serif">_polyhedron.</span><font face="arial, helvetica, sans-serif">remove_space_dimensions(<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;display:inline">​PPL::Variables_Set(​</div></font><span style="font-family:arial,helvetica,sans-serif">PPL::Variable(dim1)<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;display:inline">​)​</div>);</span></blockquote><div class="gmail_default"><span style="font-family:arial,helvetica,sans-serif"><br></span></div><div class="gmail_default"><span style="font-family:arial,helvetica,sans-serif">When </span><span style="font-family:arial,helvetica,sans-serif">_polyhedron is very large, say 60 dimensions, the merging operation becomes extremely slow. Is there a better way to merge dimensions? </span></div><div class="gmail_default"><span style="font-family:arial,helvetica,sans-serif"><br></span></div><div class="gmail_default"><span style="font-family:arial,helvetica,sans-serif">There is a operation called </span><font face="arial, helvetica, sans-serif">fold_space_dimensions. But I am not sure about its effect. </font></div><div class="gmail_default"><span style="font-family:arial,helvetica,sans-serif"><br></span></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">Thank you very much! </font></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br></div><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><font face="arial, helvetica, sans-serif" size="2">Best Regards,<br><br>Li Li<br>--<br>(<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small;display:inline">​Dr</div>) Li Li<br>Email : <a href="mailto:lilissun@gmail.com" target="_blank">lilissun@gmail.com</a></font></div><div>iTrust, Singapore University of Technology and Design</div></div></div></div></div></div></div>
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