ok.<br><br>thanks,<br>matt<br><br><div class="gmail_quote"><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div><div class="h5">On Fri, 2009-06-05 at 15:13 -0400, Matthew Galati wrote:<br>
> Is there an OSI method for adding a column at a particular index? That<br>
> is, I want to add a column as the i-th column and shift all other<br>
> columns to the right.<br>
<br>
</div></div>I don't think most (or any) optimizers that OSI supports include that<br>
functionality. CPLEX doesn't, for example. It would be quite expensive<br>
in general, and implementing it in OSI if it's not built into the solver<br>
lib is pretty horrendous--it involves unloading the problem, copying the<br>
problem or at least doing overlapping-memory moves of the data for the<br>
columns to the right of the insertion point, then reloading the problem<br>
in the solver.<br>
<br>
You're much better off just indirectly indexing columns through a vector<br>
that keeps them in the order you want. (If I were to implement it in<br>
OSI, that's how I would do it.) But for that, you are on your own.<br>
<br>
Matt<br>
<br>
--<br>
Matthew Saltzman<br>
<br>
Clemson University Math Sciences<br>
mjs AT clemson DOT edu<br>
<a href="http://www.math.clemson.edu/%7Emjs" target="_blank">http://www.math.clemson.edu/~mjs</a><br>
<br>
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</blockquote></div><br>