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<p>Mustafa,<br>
<br>
You can not create a ClpMatrixBase object. I could have defined modifyCoefficient as =0; so that user would be forced to write own modifyCoefficient if wanted to write class derived from ClpMatrixBase. But I thought this imposed less effort on user as modifyCoefficient is not much used.<br>
<br>
If you use ClpPackedMatrix which is most likely then you will just get the CoinPackedMatrix modifyCoefficient.<br>
<br>
It would probably be more efficient to get the CoinPackedMatrix representation with getPackedMatrix which is in ClpMatrixBase (and so in ClpPackedMatrix). Then use getMutableElements() and modify elements that way.<br>
<br>
John Forrest<br>
<br>
<img width="16" height="16" src="cid:1__=0ABBFE3FDFB594788f9e8a93df938@us.ibm.com" border="0" alt="Inactive hide details for "Mustafa Kilinc" ---08/20/2008 06:22:10 PM---Hello, As a subsolver to an active-set method NLP solver"><font color="#424282">"Mustafa Kilinc" ---08/20/2008 06:22:10 PM---Hello, As a subsolver to an active-set method NLP solver, I want to solve a bunch</font><br>
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<font size="2">"Mustafa Kilinc" <mrkilinc@gmail.com></font></td></tr>
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<font size="2">coin-discuss@list.coin-or.org</font></td></tr>
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<font size="2" color="#5F5F5F">Date:</font></td><td width="100%"><img width="1" height="1" src="cid:2__=0ABBFE3FDFB594788f9e8a93df938@us.ibm.com" border="0" alt=""><br>
<font size="2">08/20/2008 06:22 PM</font></td></tr>
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<font size="2">[Coin-discuss] multiple LPs with same sparsity</font></td></tr>
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<br>
<br>
<font size="4">Hello,<br>
<br>
As a subsolver to an active-set method NLP solver, I want to solve a bunch of LPs regarding Jacobian of constraints.<br>
Since at every iterate, the Jacobian matrix changes. But sparsity of constraints are not different at each iterate.<br>
Only the values in the constraints are changing but all LPs have same sparsity pattern. What is the most efficient way to do this?<br>
<br>
I intended to use <br>
<br>
void </font><a href="http://www.coin-or.org/Doxygen/Clp/class_clp_model.html#7319fac2234a6472005b2d45780ab9ee"><u><font size="4" color="#0000FF">modifyCoefficient</font></u></a><font size="4"> (int row, int column, double newElement, bool keepZero=false)<br>
<br>
But from the source code, I can see that it is not implemented in ClpMatrixBase.cpp:<br>
<br>
void <br>
ClpMatrixBase::modifyCoefficient(int row, int column, double newElement,<br>
bool keepZero)<br>
{ <br>
std::cerr<<"modifyCoefficient not supported - ClpMatrixBase"<<std::endl;<br>
abort();<br>
}<br>
<br>
Other than changing whole CoinPackedMatrix, is there a more efficient way?<br>
<br>
Thanks,<br>
Mustafa</font><tt>_______________________________________________<br>
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