XPRBvar (BCL Java Documentation)

java.lang.Object
- com.dashoptimization.XPRBvar

```
public class XPRBvar
extends java.lang.Object
```
This class represents a variable definition in BCL.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`XPRBexpr`	`add(double val)`
`XPRBexpr`	`add(XPRBexpr l)` Create a linear expression by adding a linear expression to a variable.
`XPRBexpr`	`add(XPRBvar v)`
`XPRBrelation`	`eql(double val)`
`XPRBrelation`	`eql(XPRBexpr l)` Create a linear relation of type "equal".
`XPRBrelation`	`eql(XPRBvar v)`
`void`	`fix(double val)` Fix a variable to a given value.
`XPRBrelation`	`gEql(double val)`
`XPRBrelation`	`gEql(XPRBexpr l)` Create a linear relation of type "greater or equal".
`XPRBrelation`	`gEql(XPRBvar v)`
`int`	`getColNum()` Get the column number for a variable.
`double`	`getLB()` Get the lower bound of a variable.
`double`	`getLim()` Get the integer limit for a partial integer or the semi-continuous limit for a semi-continuous or semi-continuous integer variable.
`java.lang.String`	`getName()` Get the name of a variable.
`double`	`getRCost()` Get the reduced cost value for a variable.
`double`	`getRNG(int rngtype)` Get ranging information for a variable.
`double`	`getSol()` Get the solution value for a variable.
`int`	`getType()` Get the type of a variable.
`double`	`getUB()` Get the upper bound of a variable.
`boolean`	`isValid()` Test whether a variable is correctly defined.
`XPRBrelation`	`lEql(double val)`
`XPRBrelation`	`lEql(XPRBexpr l)` Create a relation of type "less or equal".
`XPRBrelation`	`lEql(XPRBvar v)`
`XPRBexpr`	`mul(double val)` Create a linear expression by multiplying a variable with a constant.
`XPRBexpr`	`mul(XPRBexpr l)` Create an expression by multiplying a variable with an expression.
`XPRBexpr`	`mul(XPRBvar v)`
`XPRBexpr`	`neg()` Turn a variable into a linear expression by negating it.
`void`	`print()` Print out a variable.
`void`	`setDir(int type)`
`void`	`setDir(int type, double val)` Set a branching directive for a variable.
`void`	`setLB(double val)` Set a lower bound on a variable.
`void`	`setLim(double val)` Set the integer limit (= lower bound of the continuous part) for a partial integer, or the lower semi-continuous limit for a semi-continuous or semi-continuous integer variable.
`void`	`setType(int type)` Set the variable type.
`void`	`setUB(double val)` Set an upper bound on a variable.
`XPRBexpr`	`sqr()` Create an expression which is the square of a variable.
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - isValid
```
public boolean isValid()
```
    Test whether a variable is correctly defined.
```
     XPRBvar x1;
     if(x1.isValid() == false)
        System.out.println("Error in variable definition.");
 
```
  - setType
```
public void setType(int type)
```
    Set the variable type. This method changes the type of a variable that has been created previously.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x1.setType(x1, XPRB.BV);
 
```
    Parameters:
    type - variable type. Possible values:
    XPRB.PL continuous
    
    XPRB.BV binary
    
    XPRB.UI general integer
    
    XPRB.PI partial integer
    
    XPRB.SC semi-continuous
    
    XPRB.SI semi-continuous integer
  - setUB
```
public void setUB(double val)
```
    Set an upper bound on a variable.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x1.setUB(200.0);
 
```
    Parameters:
    
    val - the variable's new upper bound
  - setLB
```
public void setLB(double val)
```
    Set a lower bound on a variable.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x1.setLB(3.0);
 
```
    Parameters:
    
    val - the variable's new lower bound
  - setLim
```
public void setLim(double val)
```
    Set the integer limit (= lower bound of the continuous part) for a partial integer, or the lower semi-continuous limit for a semi-continuous or semi-continuous integer variable.
```
     XPRBprob expl2;
     XPRBvar x3;
     expl2 = new XPRBprob("example2");
     x3 = expl2.newVar("abc4", XPRB.SC, 0, 50);
     x3.setLim(5);
 
```
    Parameters:
    
    val - value of the integer limit
  - fix
```
public void fix(double val)
```
    Fix a variable to a given value. This method replaces calls to setUB(double) and setLB(double). The value val may lie outside the original bounds of the variable.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x1.fix(20.0);
 
```
    Parameters:
    
    val - value the variable is fixed to
  - setDir
```
public void setDir(int type,
                   double val)
```
    Set a branching directive for a variable. This method sets any type of branching directive available in Xpress. This may be a priority for branching on a variable (type XPRB.PR), the preferred branching direction (types XPRB.UP, XPRB.DN) or the estimated cost incurred when branching on a variable (types XPRB.PU, XPRB.PU). Several directives of different types may be set for a single variable. Note that it is only possibly to set branching directives for discrete variables (including semi-continuous and partial integer variables). Method XPRBsos.setDir(int, double) may be used to set a branching directive for a SOS.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x1.setDir(XPRB.PR, 10);
     x1.setDir(XPRB.UP);
 
```
    Parameters:
    type - directive type. Possible values:
    XPRB.PR priority
    
    XPRB.UP first branch upwards
    
    XPRB.DN first branch downwards
    
    XPRB.PU pseudocost on branching upwards
    
    XPRB.PD pseudocost on branching downwards
    val - the value of this argument depends on the type of directive to be defined. Possible values:
    XPRB.PR: priority value, integer between 1 (highest) and 1000 (least priority, default value)
    
    XPRB.UP,XPRB.DN: no input required, choose any dummy value (e.g. 0)
    
    XPRB.PU,XPRB.PD: value of pseudocost for the corresponding branch
  - setDir
```
public void setDir(int type)
```
    See Also:
    
    setDir(type, 0)
  - getName
```
public java.lang.String getName()
```
    Get the name of a variable. If the user has not defined a name the default name generated by BCL is returned.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     System.out.println(x1.getName());
 
```
    Returns:
    
    Name of the variable if method executed successfully, null otherwise
  - getColNum
```
public int getColNum()
```
    Get the column number for a variable. This method returns the column number of a variable in the matrix currently loaded in Xpress. If the variable is not part of the matrix, or if the matrix has not yet been generated, the method returns a negative value. The counting of column numbers starts with 0.
```
     XPRBprob expl2;
     XPRBvar x1;
     int vindex;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     vindex = x1.getColNum();
 
```
    Returns:
    
    Column number (integer value)
  - getType
```
public int getType()
```
    Get the type of a variable.
```
     XPRBprob expl2;
     XPRBvar x1;
     int vtype;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     vtype = x1.getType();
 
```
    Returns:
    Variable type. Possible values:
    XPRB.PL continuous
    
    XPRB.BV binary
    
    XPRB.UI general integer
    
    XPRB.PI partial integer
    
    XPRB.SC semi-continuous
    
    XPRB.SI semi-continuous integer
    
    -1 an error has occurred
  - getLB
```
public double getLB()
```
    Get the lower bound of a variable.
```
     XPRBprob expl2;
     XPRBvar x1;
     double lbound;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     lbound = x1.getLB()
 
```
    Returns:
    
    Lower bound value
  - getUB
```
public double getUB()
```
    Get the upper bound of a variable.
```
     XPRBprob expl2;
     XPRBvar x1;
     double ubound;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     ubound = x1.getUB()
 
```
    Returns:
    
    Upper bound value
  - getLim
```
public double getLim()
```
    Get the integer limit for a partial integer or the semi-continuous limit for a semi-continuous or semi-continuous integer variable.
```
     XPRBprob expl2;
     XPRBvar x3;
     double vlim;
     expl2 = new XPRBprob("example2");
     x3 = expl2.newVar("abc4", XPRB.SC, 0, 50);
     vlim = x3.getLim();
 
```
    Returns:
    
    Limit value
  - getSol
```
public double getSol()
```
    Get the solution value for a variable. The user may wish to test first whether this variable is part of the problem, for instance by checking that the column number is non-negative.
```
     XPRBprob expl2;
     XPRBvar x1;
     double solval;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     expl2.lpOptimize();
     solval = (x1.getColNum()>=0?x1.getSol():x1.getLB();
 
```
    Returns:
    
    Solution value for a variable (default 0)
  - getRCost
```
public double getRCost()
```
    Get the reduced cost value for a variable. The user may wish to test first whether this variable is part of the problem, for instance by checking that the column number is non-negative. Reduced cost information is available only after LP solving. Reduced information for MIP problems can be obtained by fixing all discrete variables to their solution values and re-solving the resulting LP problem.
```
     XPRBprob expl2;
     XPRBvar x1;
     double rcval;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     expl2.lpOptimize();
     rcval = x1.getRCost();
 
```
    Returns:
    
    Reduced cost value for a variable (default 0)
  - getRNG
```
public double getRNG(int rngtype)
```
    Get ranging information for a variable. This method can only be used after solving an LP problem. Ranging information for MIP problems can be obtained by fixing all discrete variables to their solution values and re-solving the resulting LP problem. For non-basic variables, the unit costs are always the (absolute) values of the reduced costs.
```
     XPRBprob expl2;
     XPRBvar x1;
     double ucval;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     expl2.lpOptimize();
     ucval = x1.getRNG(XPRB.UCOST);
 
```
    Parameters:
    rngtype - Ranging information type. Possible values:
    XPRB.UPACT for a variable which is at one of its bounds, the largest value which that bound can take while the current basis remains optimal
    
    XPRB.LOACT for a variable which is at one of its bounds, the smallest value which that bound can take while the current basis remains optimal
    
    XPRB.UUP the change in objective value per unit increase in the variable activity, assuming the the current basis remains optimal
    
    XPRB.UDN the change in objective value per unit decrease in the variable activity, assuming the the current basis remains optimal
    
    XPRB.UCOST the largest value which this variable's objective coefficient can take while the current basis remains optimal
    
    XPRB.LCOST the smallest value which this variable's objective coefficient can take while the current basis remains optimal
    Returns:
    
    Ranging information of the required type
  - neg
```
public XPRBexpr neg()
```
    Turn a variable into a linear expression by negating it. This methods turns a variable x into the linear expression -x.
```
     XPRBprob expl2;
     XPRBvar x1;
     XPRBexpr l;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     l = x1.neg();
 
```
    Returns:
    
    Newly created linear expression
  - add
```
public XPRBexpr add(double val)
```
    See Also:
    
    add(val)
  - add
```
public XPRBexpr add(XPRBvar v)
```
    See Also:
    
    add(v)
  - add
```
public XPRBexpr add(XPRBexpr l)
```
    Create a linear expression by adding a linear expression to a variable. Applied to a variable x, this method creates a new linear expression x+l.
```
     XPRBprob expl2;
     XPRBvar x1, x2;
     XPRBexpr l1, l2;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x2 = expl2.newVar("abc1", XPRB.PL, 0, XPRB.INFINITY);
     l1 = x1.add(17);
     l2 = x2.add(l1);
 
```
    Parameters:
    
    l - linear expression of type XPRBexpr
    
    Returns:
    
    Newly created linear expression
  - mul
```
public XPRBexpr mul(double val)
```
    Create a linear expression by multiplying a variable with a constant. Applied to a variable x, this method creates a new linear expression c*x.
```
     XPRBprob expl2;
     XPRBvar x1;
     XPRBexpr l1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     l1 = x1.mul(-4.2);
 
```
    Parameters:
    
    val - constant value
    
    Returns:
    
    Newly created linear expression
  - mul
```
public XPRBexpr mul(XPRBvar v)
```
    See Also:
    
    mul(v)
  - mul
```
public XPRBexpr mul(XPRBexpr l)
```
    Create an expression by multiplying a variable with an expression. Applied to a variable x, this method creates a new expression x*l.
```
     XPRBprob expl2;
     XPRBvar x1, x2;
     XPRBexpr l;
     XPRBexpr q;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x2 = expl2.newVar("abc1", XPRB.PL, 0, XPRB.INFINITY);
     l = x1.neg();
     q = x2.mul(l);
 
```
    Parameters:
    
    l - linear expression of type XPRBexpr
    
    Returns:
    
    Newly created quadratic expression
  - sqr
```
public XPRBexpr sqr()
```
    Create an expression which is the square of a variable. Applied to a variable x, this method creates a new expression x*x.
```
     XPRBprob expl2;
     XPRBvar x1;
     XPRBexpr q;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     q = x1.sqr();
 
```
    Returns:
    
    Newly created quadratic expression
  - lEql
```
public XPRBrelation lEql(XPRBexpr l)
```
    Create a relation of type "less or equal". Applied to a variable x, this method creates a new linear relation x<=l.
```
     XPRBprob expl2;
     XPRBvar x1, x2;
     XPRBrelation lr;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x2 = expl2.newVar("abc1", XPRB.PL, 0, XPRB.INFINITY);
     lr = x2.lEql(x1.neg());
 
```
    Parameters:
    
    l - linear expression of type XPRBexpr
    
    Returns:
    
    Newly created linear relation
  - lEql
```
public XPRBrelation lEql(XPRBvar v)
```
    See Also:
    
    lEql(v)
  - lEql
```
public XPRBrelation lEql(double val)
```
    See Also:
    
    lEql(val)
  - gEql
```
public XPRBrelation gEql(XPRBexpr l)
```
    Create a linear relation of type "greater or equal". Applied to a variable x, this method creates a new linear relation x>=l.
```
     XPRBprob expl2;
     XPRBvar x1, x2;
     XPRBrelation lr;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x2 = expl2.newVar("abc1", XPRB.PL, 0, XPRB.INFINITY);
     lr = x2.gEql(x1.neg());
 
```
    Parameters:
    
    l - linear expression of type XPRBexpr
    
    Returns:
    
    Newly created linear relation
  - gEql
```
public XPRBrelation gEql(XPRBvar v)
```
    See Also:
    
    gEql(v)
  - gEql
```
public XPRBrelation gEql(double val)
```
    See Also:
    
    gEql(val)
  - eql
```
public XPRBrelation eql(XPRBexpr l)
```
    Create a linear relation of type "equal". Applied to a variable x, this method creates a new linear relation x=l.
```
     XPRBprob expl2;
     XPRBvar x1, x2;
     XPRBrelation lr;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x2 = expl2.newVar("abc1", XPRB.PL, 0, XPRB.INFINITY);
     lr = x2.eql(x1.neg());
 
```
    Parameters:
    
    l - linear expression of type XPRBexpr
    
    Returns:
    
    Newly created linear relation
  - eql
```
public XPRBrelation eql(XPRBvar v)
```
    See Also:
    
    eql(v)
  - eql
```
public XPRBrelation eql(double val)
```
    See Also:
    
    eql(val)
  - print
```
public void print()
```
    Print out a variable. This method prints out name and bounds for continuous, binary and integer variables; name, bounds and integer limit or lower semi-continuous limit for partial integer, semi-continuous, and semi-continuous integer variables. If a solution value is available, this value is printed instead of the bounds.
```
     XPRBprob expl2;
     XPRBvar x1;
     expl2 = new XPRBprob("example2");
     x1 = expl2.newVar("abc3", XPRB.UI, 1, 100);
     x1.print();
 
```
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
    
    See Also:
    
    getName()

Class XPRBvar

Method Summary

Methods inherited from class java.lang.Object

Method Detail

isValid

setType

setUB

setLB

setLim

fix

setDir

setDir

getName

getColNum

getType

getLB

getUB

getLim

getSol

getRCost

getRNG

neg

add

add

add

mul

mul

mul

sqr

lEql

lEql

lEql

gEql

gEql

gEql

eql

eql

eql

print

toString