scalation.minima

QuadraticSimplex

class QuadraticSimplex extends Error

This class solves Quadratic Programming (QP) problems using the Quadratic Simplex Algorithm. Given a constraint matrix 'a', constant vector 'b', cost matrix 'q' and cost vector 'c', find values for the solution/decision vector x that minimize the objective function f(x), while satisfying all of the constraints, i.e.,

minimize f(x) = 1/2 x q x + c x subject to a x <= b, x >= 0

Creates an MM-by-NN simplex tableau. This implementation is restricted to linear constraints (a x <= b) and q being a positive semi-definite matrix. Pivoting must now also handle nonlinear complementary slackness

See also

http://www.engineering.uiowa.edu/~dbricker/lp_stacks.html

Linear Supertypes
Error, AnyRef, Any
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. QuadraticSimplex
  2. Error
  3. AnyRef
  4. Any
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Instance Constructors

  1. new QuadraticSimplex(a: MatrixD, b: VectorD, q: MatrixD, c: VectorD, x_B: Array[Int] = null)

    a

    the M-by-N constraint matrix

    b

    the M-length constant/limit vector

    q

    the M-by-N cost/revenue matrix (second order component)

    c

    the N-length cost/revenue vector (first order component)

    x_B

    the initial basis (set of indices where x_i is in the basis)

Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any
  3. final def ##(): Int

    Definition Classes
    AnyRef → Any
  4. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  5. final def ==(arg0: Any): Boolean

    Definition Classes
    Any
  6. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  7. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  8. def comple(l: Int): Int

    Return l's complementary variable.

    Return l's complementary variable.

    l

    whose complement

  9. def dual: VectorD

    Return the dual solution vector (y).

  10. def entering(): Int

    Find a variable x_l to enter the basis.

    Find a variable x_l to enter the basis. Determine the index of entering variable corresponding to column l. Neighter the variable nor its complement may be in the current basis. Return -1 to indicate no such column.

  11. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  12. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  13. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  14. def flaw(method: String, message: String): Unit

    Show the flaw by printing the error message.

    Show the flaw by printing the error message.

    method

    the method where the error occurred

    message

    the error message

    Definition Classes
    Error
  15. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any
  16. def hashCode(): Int

    Definition Classes
    AnyRef → Any
  17. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any
  18. val k: Int

  19. val l: Int

  20. def leaving(l: Int): Int

    Find the best variable x_k to leave the basis given that x_l is entering.

    Find the best variable x_k to leave the basis given that x_l is entering. Determine the index of the leaving variable corresponding to row k using the Min-Ratio Rule. Return -1 to indicate no such row.

    l

    the entering variable (column)

  21. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  22. final def notify(): Unit

    Definition Classes
    AnyRef
  23. final def notifyAll(): Unit

    Definition Classes
    AnyRef
  24. def objValue(x: VectorD): Double

    Return the optimal objective function value (f(x) = 1/2 x q x + c x).

    Return the optimal objective function value (f(x) = 1/2 x q x + c x).

    x

    the primal solution vector

  25. def pivot(k: Int, l: Int): Unit

    Pivot on entry (k, l) using Gauss-Jordan elimination to replace variable x_k with x_l in the basis.

    Pivot on entry (k, l) using Gauss-Jordan elimination to replace variable x_k with x_l in the basis.

    k

    the leaving variable (row)

    l

    the entering variable (column)

  26. def primal: VectorD

    Return the primal solution vector (x).

  27. def setBasis(j: Int = N, l: Int = M): Array[Int]

    There are M+N variables, N decision and M slack variables, of which, for each iteration, M are chosen for a Basic Feasible Solution (BFS).

    There are M+N variables, N decision and M slack variables, of which, for each iteration, M are chosen for a Basic Feasible Solution (BFS). The the variables not in the basis are set to zero. Setting j to N will start with the slack variables in the basis (only works if b >= 0).

    j

    the offset to start the basis

    l

    the size of the basis

  28. def showTableau: Unit

    Show the current basis and tableau.

  29. def solve(): (VectorD, Double)

    Run the simplex algorithm starting from the initial BFS and iteratively find a non-basic variable to replace a variable in the current basis so long as the objective improves.

  30. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  31. def tableau: MatrixD

    Return the tableau (t).

  32. def toString(): String

    Definition Classes
    AnyRef → Any
  33. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  34. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  35. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  36. var x_B: Array[Int]

    the initial basis (set of indices where x_i is in the basis)

Inherited from Error

Inherited from AnyRef

Inherited from Any

Ungrouped