scale.common
Class Cost

java.lang.Object
  scale.common.Cost

public class Cost
extends java.lang.Object

This class implements a cost model based on a power expansion.

$Id: Cost.java,v 1.15 2007-05-15 17:36:06 burrill Exp $

Copyright 2008 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.

The cost model is the sum of a set of terms. Each term is of the form

 c*x**n
 

Constructor Summary

Cost()
Create a cost with one term with a zero coefficient, power of 0.

Cost(double coefficient, int power)
Create a cost with one term with the given coefficient, etc.

Method Summary

void	add(Cost cost) Add all the terms of another Cost to this one.
void	add(double coefficient, int power) Add new term to cost expression:
void	add(int c) Increment cost expression by constant:
double	calcCost(double x) Return the cost based on value x.
Cost	copy() Return a deep copy of this cost.
void	divide(double c) Divide cost expression by constant:
Cost	getHighestOrderTerm() Return the term with the highest exponent.
boolean	lessThan(Cost cost) Return true if this cost is less than the specified cost.
void	multiply(Cost cost) Multiply all the terms of this loop with the terms of the argument cost.
void	multiply(double mfactor) Multiply cost expression by constant:
void	multiply(double coefficient, int power) Multiply cost expression by cost term:
int	order() Return the order of the polynomial: the power of the largest non-zero term.
void	reset() Set all terms to 0.
void	subtract(double coefficient, int power) Add new term to cost expression:
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Cost

public Cost()

Create a cost with one term with a zero coefficient, power of 0.

Cost

public Cost(double coefficient,
            int power)

Create a cost with one term with the given coefficient, etc.

Parameters:

coefficient - of the cost term

power - of the cost term

Method Detail

calcCost

public double calcCost(double x)

Return the cost based on value x.

reset

public void reset()

Set all terms to 0.

add

public void add(int c)

Increment cost expression by constant:

add

public void add(double coefficient,
                int power)

Add new term to cost expression:

add

public void add(Cost cost)

Add all the terms of another Cost to this one.

subtract

public void subtract(double coefficient,
                     int power)

Add new term to cost expression:

multiply

public void multiply(double mfactor)

Multiply cost expression by constant:

multiply

public void multiply(double coefficient,
                     int power)

Multiply cost expression by cost term:

multiply

public void multiply(Cost cost)

Multiply all the terms of this loop with the terms of the argument cost.

divide

public void divide(double c)

Divide cost expression by constant:

order

public int order()

Return the order of the polynomial: the power of the largest non-zero term.

getHighestOrderTerm

public Cost getHighestOrderTerm()

Return the term with the highest exponent.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

lessThan

public boolean lessThan(Cost cost)

Return true if this cost is less than the specified cost.

copy

public Cost copy()

Return a deep copy of this cost.