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2  Building and Modifying a Model
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4  Basic Model Classes
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6  Getting at the Solution
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8  Building and Modifying a Model
9  </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch02s03.html">Prev</a> </td><th width="60%" align="center">Chapter 2. 
10  Basic Model Classes
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12  Building and Modifying a Model
13  </h2></div></div></div><p>
14  Rather than reading a model from an MPS file we can load a model from arrays
15  in memory.  There are various <tt class="function">loadProblem</tt> methods which
16  are similar to those in OSI.  It is easy to add more such methods to CLP if the need arises.
17  </p><p>We can copy in integer information by
18  <tt class="function">copyInIntegerInformation(const char * array)</tt> where array
19  is 0 or 1 to say integer and we can drop existing information by
20  <tt class="function">deleteIntegerInformation()</tt>.  There are various ways of
21  changing the size of a model.  The simplest is by the use of the method
22  <tt class="function">resize(newNumberRows,newNumberColumns)</tt> - this will either
23  truncate the model or add "default" rows or columns - a default row
24  has lower bound of -infinity and upper bound of +infinity, while a default
25  column has zero cost, zero lower bound and an upper bound of +infinity.
26  </p><p>
27  Normally we would use <tt class="function">deleteRows</tt>,
28  <tt class="function">addRows</tt>, <tt class="function">deleteColumns</tt> and
29  <tt class="function">addColumns</tt>, where the <tt class="function">add</tt> methods
30  will also add in the elements.  A potentially very useful way of modifying a model is strictly a
31  constructor.  Given a large model and a list of rows and a list of columns it
32  constructs the model as a subset of the large model.  It is possible to change
33  the order of the columns/rows and to duplicate columns/rows.  So a list of
34  columns 4,4,1,0 will create a new model where the first two columns are copies
35  of column 4 in original model and the next two are the first two of original
36  model in reverse order.  This can be useful to form a model with piecewise
37  linear costs by duplicating columns and then modifying bounds and costs.
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39  Getting at the Solution
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