com.opttek.optquest
Class COptQuestStringObjective

java.lang.Object
  com.opttek.optquest.COptQuestObjective
      com.opttek.optquest.COptQuestStringObjective

public class COptQuestStringObjective

extends COptQuestObjective

The COptQuestStringObjective class is used to define an objective function using a mathematical expression. The expression may be linear or non-linear. For example, the objective may be to minimize "2*Var1 + 3*Var2 + 1.5*Var3". "Var1", "Var2" and "Var3" must be names that were assigned to COptQuestVariable objects. If a variable name contains non-alphanumeric characters such as blanks, the names should be enclosed in square brackets in the equation string. For example, "2*[Var 1] + 3*[Var 2] + 1.5*[Var 3] <= 100"

The following mathematical functions are supported and can be used in the mathematical expression:

• min(x,y) Returns the smaller value of x and y
• max(x,y) Returns the larger value of x and y
• sqrt(x) Returns the square root of x
• log(x) Returns the logarithm of x
• log10(x) Returns the base 10 logarithm of x
• pow(x,y) Returns x raise to the power y
• exp(x) Returns e raised to the power x
• abs(x) Returns the absolute value of x
• pi The mathematical constant pi (3.141159)
• e The mathematical constant e (2.718)
• rand() Returns a random number between 0 and 1
• fmod(x,y) Returns the remainder of x/y
• floor(x) Returns the largest whole number less than or equal to x
• ceil(x) Return the smallest whole number greater than or equal to x
• sin(x) Returns the sine of x where x is an angle in radians
• cos(x) Returns the cosine of x where x is an angle in radians
• tan(x) Returns the tangent of x where x is an angle in radians
• sinh(x) Returns the hyperbolic sine of x where x is an angle in radians
• cosh(x) Returns the hyperbolic cosine of x where x is an angle in radians
• tanh(x) Returns the hyperbolic tangent of x where x is an angle in radians
• asin(x) Returns the arcsine of x in the range -n/2 to n/2 radians. x is between -1 and 1.
• asin(x) Returns the arcsine of x in the range -n/2 to n/2 radians. x is between -1 and 1.
• acos(x) Returns the arccosine of x in the range 0 to n radians. x is between -1 and 1.
• atan(x) Returns the arcstangent of x in the range -pi/2 to pi/2 radians. if x is 0, atan returns 0.
• atan2(x,y) Returns the arctangent of y/x in the range -pi to pi radians. If both x and y are 0, the function returns 0.
• DtoR(x) Converts degrees to radians.
• RtoD(x) Converts radians to degrees.

Constructor Summary

COptQuestStringObjective()
Default constructor

COptQuestStringObjective(java.lang.String expression)

Method Summary

boolean	GetCheckLinear() Returns true if the objective equation should be checked for linearity.
boolean	IsLinear() Returns true if the expression is linear.
void	SetCheckLinear(boolean Value) If true, the objective should be checked for linearity.
void	SetEquation(java.lang.String equation) Sets the mathematical expression that defines the objective.

Methods inherited from class com.opttek.optquest.COptQuestObjective

GetBestFeasible, GetBestValue, GetCurrentFeasible, GetCurrentFeasible, GetCurrentValue, GetCurrentValue, GetNthBestFeasible, GetNthBestValue, IsMaximize, IsMinimize, SetCurrentValue, SetCurrentValue, SetMaximize, SetMinimize

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

COptQuestStringObjective

public COptQuestStringObjective()

Default constructor

COptQuestStringObjective

public COptQuestStringObjective(java.lang.String expression)

Method Detail

IsLinear

public boolean IsLinear()

Returns true if the expression is linear. Returns false if it is not. This method should be called after the optmization has started or after calling COptQuestOptmization::ValidateEquation(). IsLinear() will return false if it is called before one of these methods.

Overrides:

IsLinear in class COptQuestObjective

Returns:

true if the constraints equation is linear. Returns false if it is not linear or it's state has not been checked.

SetEquation

public void SetEquation(java.lang.String equation)
                 throws COptQuestException

Sets the mathematical expression that defines the objective.

Parameters:

equation - - mathematical expression that defines the objective of the optimization

Throws:

COptQuestException

SetCheckLinear

public void SetCheckLinear(boolean Value)

If true, the objective should be checked for linearity. Linear objectives can be solved using the OptQuest linear program. The default value is true.

Parameters:

Value - - true if the mathematical expression should be checked for linearity. False if it should not be checked.

GetCheckLinear

public boolean GetCheckLinear()

Returns true if the objective equation should be checked for linearity. Returns false if the linearity check has been turned off by calling SetCheckLinear(false)

Returns:

boolean indicating the whether linearity checking is turned on or off.