towr::SoftConstraint Class Reference

Converts a constraint to a cost by weighing the quadratic violations. More...

`#include <soft_constraint.h>`

List of all members.

Public Member Functions

SoftConstraint (const ConstraintPtr &constraint)
Creates a soft constraint (=cost) from a hard constraint.
virtual ~SoftConstraint ()

Private Member Functions

VecBound GetBounds () const final
Jacobian GetJacobian () const override
The row-vector of derivatives of the cost term.
VectorXd GetValues () const override
average value of each upper and lower bound.
void SetVariables (const VectorXd &x) final

Private Attributes

VectorXd b_
ConstraintPtr constraint_
VectorXd W_
weights how each constraint violation contributes to the cost.

Detailed Description

Converts a constraint to a cost by weighing the quadratic violations.

Let constraint g(x) R^m with upper bound b_u and lower bound b_l. Let

g'(x) = g(x) - 0.5(b_u+b_l) = g(x) - b

And it's derivative

dg'(x)/dx = J(x).

Define a cost as

c(x) = 0.5 * g'^T * W * g', where W = diag(w1,...,wm).

Then the gradient of the cost is defined as:

dc(x)/dx = (g'(x)^T * W * J)^T = J^T * W * (g(x)-b).

Definition at line 59 of file soft_constraint.h.

Constructor & Destructor Documentation

 towr::SoftConstraint::SoftConstraint ( const ConstraintPtr & constraint )

Creates a soft constraint (=cost) from a hard constraint.

Parameters:
 constraint The fully initialized constraint.

Weights are set to identity, so each constraint violation contributes equally to the cost.

Definition at line 34 of file soft_constraint.cc.

 virtual towr::SoftConstraint::~SoftConstraint ( ) ` [virtual]`

Member Function Documentation

 VecBound towr::SoftConstraint::GetBounds ( ) const` [inline, private]`

Definition at line 93 of file soft_constraint.h.

 SoftConstraint::Jacobian towr::SoftConstraint::GetJacobian ( ) const` [override, private]`

The row-vector of derivatives of the cost term.

dc(x)/dx = J^T * W * (g-b)

Definition at line 61 of file soft_constraint.cc.

 SoftConstraint::VectorXd towr::SoftConstraint::GetValues ( ) const` [override, private]`

average value of each upper and lower bound.

The quadratic constraint violation transformed to a cost.

c(x) = 0.5 * (g-b)^T * W * (g-b)

Definition at line 53 of file soft_constraint.cc.

 void towr::SoftConstraint::SetVariables ( const VectorXd & x ) ` [inline, private]`

Definition at line 94 of file soft_constraint.h.

Member Data Documentation

 VectorXd towr::SoftConstraint::b_` [private]`

Definition at line 76 of file soft_constraint.h.

 ConstraintPtr towr::SoftConstraint::constraint_` [private]`

Definition at line 74 of file soft_constraint.h.

 VectorXd towr::SoftConstraint::W_` [private]`

weights how each constraint violation contributes to the cost.

Definition at line 75 of file soft_constraint.h.

The documentation for this class was generated from the following files:

towr
Author(s): Alexander W. Winkler
autogenerated on Mon Apr 15 2019 02:42:32