Interpolation

java.lang.Object
- ptolemy.backtrack.automatic.ptolemy.math.Interpolation

All Implemented Interfaces:

Rollbackable
```
public class Interpolation
extends java.lang.Object
implements Rollbackable
```
This class provides algorithms to do interpolation. Currently, zero, first, and third order interpolations are supported. These are the interpolation orders most often used in practice. zero order interpolation holds the last reference value; first order does linear interpolation; and third order interpolation is based on the Hermite curves in chapter 11 of "Computer Graphic, Principles and Practice", by Foley, van Dam, Feiner and Hughes, 2nd ed. in C, 1996.
The setValues() method specifies the reference values as a double array. setIndexes() specifies the indexes of those values as an int array. These two arrays must have the same length, and the indexes must be increasing and non-negative; otherwise an exception will be thrown. The values are periodic if a positive period is set by setPeriod(). In this case, the period must be greater than the largest index, and values within the index range 0 to (period-1) are repeated indefinitely. If the period is zero, the values are not periodic, and the values outside the range of the indexes are considered to be 0.0. The interpolation order is set by setOrder().
The default reference values are {1.0, 0.0} and the indexes are {0, 1}. The default period is 2 and the order is 0.

Since:

Ptolemy II 0.4

Version:

$Id$

Author:

Sarah Packman, Yuhong Xiong

Pt.AcceptedRating:

red (cxh)

Pt.ProposedRating:

Yellow (yuhong)

Field Summary

Fields
Modifier and Type Field and Description

protected Checkpoint $CHECKPOINT

protected CheckpointRecord $RECORD$$CHECKPOINT

Fields
Modifier and Type	Field and Description
`protected Checkpoint`	`$CHECKPOINT`
`protected CheckpointRecord`	`$RECORD$$CHECKPOINT`

Constructor Summary

Constructors
Constructor and Description

Interpolation()
Construct an instance of Interpolation using the default parameters.

Constructors
Constructor and Description
`Interpolation()` Construct an instance of Interpolation using the default parameters.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`$COMMIT(long timestamp)` Commit changes up to the given timestamp, but not including changes made at timestamp and afterward.
`Checkpoint`	`$GET$CHECKPOINT()` Get the checkpoint object that monitors this rollbackable object.
`void`	`$RESTORE(long timestamp, boolean trim)` Restore a previous state to all the private fields of this rollbackable object.
`java.lang.Object`	`$SET$CHECKPOINT(Checkpoint checkpoint)` Set the checkpoint object of this rollbackable object.
`int[]`	`getIndexes()` Return the reference indexes.
`int`	`getOrder()` Return the interpolation order.
`int`	`getPeriod()` Return the value repetition period.
`double[]`	`getValues()` Return the reference values.
`double`	`interpolate(int index)` Return the interpolation result for the specified index.
`void`	`setIndexes(int[] indexes)` Set the reference indexes.
`void`	`setOrder(int order)` Set the interpolation order.
`void`	`setPeriod(int period)` Set the value repetition period.
`void`	`setValues(double[] values)` Set the reference values.

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

- Field Detail
  - $CHECKPOINT
```
protected transient Checkpoint $CHECKPOINT
```
  - $RECORD$$CHECKPOINT
```
protected transient CheckpointRecord $RECORD$$CHECKPOINT
```
- Constructor Detail
  - Interpolation
```
public Interpolation()
```
    Construct an instance of Interpolation using the default parameters.
- Method Detail
  - getIndexes
```
public int[] getIndexes()
```
    Return the reference indexes.
    
    Returns:
    
    An int array.
    
    See Also:
    
    setIndexes(int[])
  - getOrder
```
public int getOrder()
```
    Return the interpolation order.
    
    Returns:
    
    An int.
    
    See Also:
    
    setOrder(int)
  - getPeriod
```
public int getPeriod()
```
    Return the value repetition period.
    
    Returns:
    
    An int.
    
    See Also:
    
    setPeriod(int)
  - getValues
```
public double[] getValues()
```
    Return the reference values.
    
    Returns:
    
    An double array.
    
    See Also:
    
    setValues(double[])
  - interpolate
```
public double interpolate(int index)
```
    Return the interpolation result for the specified index.
    
    Parameters:
    
    index - The point of interpolation. Can be negative
    
    Returns:
    
    A double.
    
    Throws:
    
    java.lang.IllegalStateException - If the index and value arrays do not have the same length, or the period is not 0 and not greater than the largest index.
  - setIndexes
```
public void setIndexes(int[] indexes)
```
    Set the reference indexes.
    
    Parameters:
    
    indexes - An int array.
    
    Throws:
    
    java.lang.IllegalArgumentException - If the argument array is not increasing and non-negative.
    
    See Also:
    
    getIndexes()
  - setOrder
```
public void setOrder(int order)
```
    Set the interpolation order.
    
    Parameters:
    
    order - An int.
    
    Throws:
    
    java.lang.IllegalArgumentException - If the order is not 0, 1, or 3.
    
    See Also:
    
    getOrder()
  - setPeriod
```
public void setPeriod(int period)
```
    Set the value repetition period.
    
    Parameters:
    
    period - An int.
    
    Throws:
    
    java.lang.IllegalArgumentException - If the period is negative.
    
    See Also:
    
    getPeriod()
  - setValues
```
public void setValues(double[] values)
```
    Set the reference values.
    
    Parameters:
    
    values - A double array.
    
    See Also:
    
    getValues()
  - $COMMIT
```
public void $COMMIT(long timestamp)
```
    Description copied from interface: Rollbackable
    
    Commit changes up to the given timestamp, but not including changes made at timestamp and afterward.
    
    Specified by:
    
    $COMMIT in interface Rollbackable
    
    Parameters:
    
    timestamp - The timestamp.
  - $RESTORE
```
public void $RESTORE(long timestamp,
                     boolean trim)
```
    Description copied from interface: Rollbackable
    
    Restore a previous state to all the private fields of this rollbackable object.
    
    Specified by:
    
    $RESTORE in interface Rollbackable
    
    Parameters:
    
    timestamp - The timestamp taken at the time when the previous state was recorded.
    
    trim - Whether to delete the records used for the rollback.
    
    See Also:
    
    Checkpoint.rollback(long, boolean)
  - $GET$CHECKPOINT
```
public final Checkpoint $GET$CHECKPOINT()
```
    Description copied from interface: Rollbackable
    
    Get the checkpoint object that monitors this rollbackable object.
    
    Specified by:
    
    $GET$CHECKPOINT in interface Rollbackable
    
    Returns:
    
    The checkpoint object.
  - $SET$CHECKPOINT
```
public final java.lang.Object $SET$CHECKPOINT(Checkpoint checkpoint)
```
    Description copied from interface: Rollbackable
    
    Set the checkpoint object of this rollbackable object. A merge operation is performed on the current checkpoint object and the new checkpoint object, so that the two checkpoint objects monitor the same set of objects when this function returns.
    
    Specified by:
    
    $SET$CHECKPOINT in interface Rollbackable
    
    Parameters:
    
    checkpoint - The new checkpoint object.
    
    Returns:
    
    This rollbackable object itself.
    
    See Also:
    
    Checkpoint.setCheckpoint(Checkpoint)

Class Interpolation

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

$CHECKPOINT

$RECORD$$CHECKPOINT

Constructor Detail

Interpolation

Method Detail

getIndexes

getOrder

getPeriod

getValues

interpolate

setIndexes

setOrder

setPeriod

setValues

$COMMIT

$RESTORE

$GET$CHECKPOINT

$SET$CHECKPOINT