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<div class="moz-cite-prefix">Hi Wei Kai,<br>
<br>
I'm not sure what you mean. Do you want to change a constraint
from, say, less-equal to larger-equal? Every linear constraint in
SCIP has a left-hand side and a right-hand side. If you have an
equation, both are equal, if you have an inequality, either the
lhs is -infinity or the rhs is +infinity. You can change this to
adjust your constraint sense, but this is only allowed in the
problem creation stage, once solving started, you cannot change
the lhs or rhs of a constraint anymore - this constraint may have
led to some nodes being cut off, you cannot just relax it now and
expect to get the correct solution.<br>
<br>
But if you have the slack variable explicitly in your model, you
could just branch on it? On the other hand, you may create new
linear constraints and add them to a local node, but not change
them.<br>
<br>
Best,<br>
Gerald<br>
<br>
On 12.01.2016 07:45, <a class="moz-txt-link-abbreviated" href="mailto:weikaimas@163.com">weikaimas@163.com</a> wrote:<br>
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<blockquote cite="mid:2016011214450785950413@163.com" type="cite">
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<div><span></span>Hi all,</div>
<div><span style="font-family: ''; font-size: 10.5pt; line-height:
1.5; background-color: window;"> </span></div>
<div><span style="font-family: ''; font-size: 10.5pt; line-height:
1.5; background-color: window;"> I implement a B&P
algorithm. I consider a branching stratege base on slack
variables of a set of constraint.</span></div>
<div>How can I change the sense of the constraint and record the
information in consdata of current node.</div>
<div><br>
</div>
<div>Thank you all.</div>
<div><br>
</div>
<div>Best,</div>
<div>Wei kai</div>
</blockquote>
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