Most of the parameter setting in CBC is done through CbcModel methods. The most commonly used set and get methods are listed in Table 2.2.
Table 2.2. Useful Set and Get Methods in CbcModel
| Method(s) | Description |
|---|---|
| bool setMaximumNodes(int value) int getMaximumNodes() const bool setMaximumSeconds(double value) double getMaximumSeconds() bool setMaximumSolutions(double value) double getMaximumSolutions() const | These set methods tell CBC to stop after a given number of nodes, seconds, or solutions is reached. The get methods return the corresponding values. |
| bool setIntegerTolerance(double value) const double getIntegerTolerance() const | An integer variable is deemed to be at an integral value if it is no further than this value (tolerance) away. |
| bool setAllowableGap(double value) double getAllowableGap() const bool setAllowablePercentageGap(double value) double getAllowablePercentageGap() const bool setAllowableFractionGap(double value) double getAllowableFractionGap() const | CbcModel returns if the gap between the best known solution and the best possible solution is less than this value, or as a percentage, or a fraction. |
| void setNumberStrong(double value) int numberStrong() [a] const | These methods set or get the maximum number of candidates at a node to be evaluated for strong branching. |
| void setPrintFrequency(int value) int printFrequency() const | Controls the number of nodes evaluated between status prints. Print frequency has a very slight overhead, if value is small. |
| int getNodeCount() const | Returns number of nodes evaluated in the search. |
| int numberRowsAtContinuous() const | Returns number of rows in the problem when handed to the solver (i.e., before cuts where added). Commonly used in implementing heuristics. |
| int numberIntegers() const const int * integerVariable() const | Returns number of integer variables and an array specifying them. |
| bool isBinary(int colIndex) const bool isContinuous(int colIndex) const bool isInteger(int colIndex) const | Returns information on variable colIndex. OSI methods can be used to set these attributes (before handing the model to CbcModel). |
| double getObjValue() const | This method returns the best objective value so far. |
| double getCurrentObjValue() const | This method returns the current objective value. |
| const double * getObjCoefficients() const | This method return the objective coefficients. |
| const double * getRowLower() const const double * getRowUpper() const const double * getColLower() const const double * getColUpper() const | These methods return the lower and upper bounds on row and column activities. |
| const CoinPackedMatrix * getMatrixByRow() const | This method returns a pointer to a row copy of matrix stored as a CoinPackedMatrix which can be further examined. |
| const CoinPackedMatrix * getMatrixByCol() const | This method returns a pointer to a column copy of matrix stored as a CoinPackedMatrix which can be further examined. |
| CoinBigIndex getNumElements() const[b] | Returns the number of nonzero elements in the problem matrix. |
| void setObjSense(double value) double getObjSense() const | These methods set and get the objective sense. The parameter value should be +1 to minimize and -1 to maximize. |
[a] This methods (and some of the other) do not follow the "get" convention. The convention has changed over time and there are still some inconsistencies to be cleaned up. [b] CoinBigIndex is a typedef which in most cases is the same as int. | |