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<div class="moz-cite-prefix">Richi,<br>
<br>
There should not be any issues with using features in parallel.<br>
<br>
The developments with SOS etc all took place during the 70's
mainly at the consultancy company - Scicon. Those were the days
when a company could write optimization software mainly to be used
for its clients. LP/IP codes included - Alligator (great name
derived from a technique akin to linear programming - very bad
code), Umpire (Unified Mathematical Programming incorporating
refinements and extensions - very good code) and Sciconic (boring
name).<br>
<br>
You may find papers mostly authored by Martin Beale (you may also
find Tomlin and Forrest in some of them). They all involve very
simple branching techniques to model increasingly complex ideas -
so Linked Ordered Sets can directly model x*f(y). A lot of these
are in Cbc and it is easy for any user to extend them - Open
Source can bring back some of the links between algorithm and
application/customer.<br>
<br>
Find some of the papers, but you may find it easier to get clear
in your mind what techniques you would like to exist and then pose
questions in this forum to help other people. <br>
<br>
John<br>
<br>
On 29/01/18 16:47, richi arora wrote:<br>
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<div><span style="color: rgb(38, 40, 42);">Hi John</span><br>
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<div>I tried sos and semi-continuous variables in
trunk. It works fine for the tests that I did.</div>
<div>Thanks for taking the task up and providing
the implementation for lp files.</div>
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<div>Any plans when same might be available in a
release ?</div>
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<div>However I was eager to know about:</div>
<div>-> If you can point me to any
tutorial/book that can tell best way to use semi
variables and SOS variables to get best
performance. (PS: I was till now using binary
variables but performance took a hit)</div>
<div>-> Are there in issues if I use semis or
sos along with parallelizing feature of cbc ?</div>
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<div>I plan to use parallelizing feature to
improve performance.</div>
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<div>Thanks</div>
<div>Richi Arora</div>
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<div> On Friday 19 January 2018, 11:01:48 PM
IST, richi arora
<a class="moz-txt-link-rfc2396E" href="mailto:richi_arora_ra@yahoo.co.in"><richi_arora_ra@yahoo.co.in></a> wrote: </div>
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<div>ah ok.</div>
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<div>Any link or info as in how can I
use SOS or Lotsize in lp file ?</div>
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<div>I tried sos but still cbc crashed
eg:</div>
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<pre style="color:rgb(0, 0, 0);">min: -x1 -x2 -3 x3 -2 x4 -2 x5;
c1: -x1 -x2 +x3 +x4 <= 30;
c2: +x1 +x3 -3 x4 <= 30;
x1 <= 40;
x2 <= 1;
x5 <= 1;
sos
SOS1: x1, x2, x3, x4 <= 2;
SOS2: x2, x3, x4, x5 <= 3;</pre>
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<div>Thanks</div>
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<div>Richi Arora</div>
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