[CHiPPS] Asking for methods to get the number of Non-integervariables

[Yan Xu]

I see what you meant now. In your terminology, the non-integer variables are those integer variables that are fractional.   Blis doesn’t store this info, but you can check this after solving a LP relaxation, like line 408 of BlisTreeNode.cpp.

    /** Test the current LP solution for feasiblility.
                Scan all objects for indications of infeasibility. This is broken down
                into simple integer infeasibility (\p numIntegerInfs)
                and all other reports of infeasibility(\p numObjectInfs). */
    virtual BlisSolution *feasibleSolution(int & numIntegerInfs,
                                           int & numObjectInfs);




From: 190564342 at qq.com [mailto:190564342 at qq.com] On Behalf Of ???
Sent: Tuesday, April 23, 2013 9:49 AM
To: Yan Xu; chipps
Cc: geogrid
Subject: Re:RE: [CHiPPS] Asking for methods to get the number of Non-integervariables


Dear sir,
        You know, my problem is a BIP one.
        Accroding to my knowledge, when using B&B, the number of Non-integer variables will decrease, when a solution is gotten, the number of Non-integer variables becomes zero.
        What I want is this number of Non-integer variables which is changing along whit the B&B process.
     But I have looked at the code, after the model is set up, both the numCols_ numIntObjects_ seem to be unchanged when the tree is being searched.
    Will the difference of numIntObjects_ and numCols_ meet my need?



------------------ Original ------------------
From:  "Yan Xu"<Yan.Xu at sas.com<mailto:Yan.Xu at sas.com>>;
Date:  Tue, Apr 23, 2013 09:21 PM
To:  "化高峰"<shimuxi at gmail.com<mailto:shimuxi at gmail.com>>; "chipps"<chipps at list.coin-or.org<mailto:chipps at list.coin-or.org>>;
Cc:  "geogrid"<geogrid at gmail.com<mailto:geogrid at gmail.com>>;
Subject:  RE: [CHiPPS] Asking for methods to get the number of Non-integervariables

    /** Get number of columns. */
int getNumCols() { return lpSolver_->getNumCols();

    /** Get number of integers. */
int getNumIntObjects() const { return numIntObjects_; }


After BlisModel is set up, you can use the above two funcitons to get the number of variables, and the number of integers, then the difference of this two numbers is the number of non-integer variables.

Also, BlisModel has data member numCols_ and numIntObjects_.  The difference of them is also the number of non-integer variables.

Hope this helps,
-Yan




From: chipps-bounces at list.coin-or.org<mailto:chipps-bounces at list.coin-or.org> [mailto:chipps-bounces at list.coin-or.org] On Behalf Of ???
Sent: Tuesday, April 23, 2013 4:56 AM
To: chipps
Cc: geogrid
Subject: [CHiPPS] Asking for methods to get the number of Non-integer variables

Dear sir,
        I am looking a way to get the number of Non-integer variables in BLIS.
        Could you tell me some methods to calculate it?
        Or, in which function could I get the number of Non-integer variables in BLIS?

        Thank you very much for early reply!
Best Regards!

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