CardinalSpline (Macrofocus High-D API for Swing SpecificationA good and efficient starting point is the use of the SwingHighD component. It contains all the information to get started within minutes!To use this API, please make sure you have at least (this is the absolute minimum) the macrofocus-high-d-swing.jar, macrofocus-high-d.jar, macrofocus-common.jar, macrofocus-visualization.jar, and macrofocus-slider.jar libraries in your class path.)

java.lang.Object
- com.macrofocus.high_d.parallelcoordinates.geometry.curve.Curve
- - com.macrofocus.high_d.parallelcoordinates.geometry.curve.CardinalSpline

```
public class CardinalSpline
extends Curve
```
The Cardinal-spline passes through the points in the control-path specified by the group-iterator. However, the curve does not pass through the first or the last control-point, it begins at the second control-point and ends at the second last control-point.

There is a single parameter, alpha, that gives some control over the shape of the curve. When the value of alpha is 0.5 the curve becomes the CatmullRomSpline. Figure 1 shows an example of a CardinalSpline.

See Also:

CatmullRomSpline

Constructor Summary

Constructors
Constructor Description

CardinalSpline(ControlPath cp, GroupIterator gi)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`appendTo(com.macrofocus.high_d.parallelcoordinates.geometry.curve.MultiPath mp)`	The requirements for this curve are the group-iterator must be in-range and have a group size of at least 4.
`protected void`	`eval(double[] p)`	The eval method evaluates a point on a curve given a parametric value "t".
`double`	`getAlpha()`	Returns the value of alpha.
`int`	`getSampleLimit()`	Returns a value of 1.
`void`	`setAlpha(double a)`	Sets the value of alpha.

Methods inherited from class com.macrofocus.high_d.parallelcoordinates.geometry.curve.Curve
getConnect, getControlPath, getGroupIterator, resetMemory, setConnect

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

- Constructor Detail
  - CardinalSpline
```
public CardinalSpline(ControlPath cp,
                      GroupIterator gi)
```
- Method Detail
  - eval
```
protected void eval(double[] p)
```
    The eval method evaluates a point on a curve given a parametric value "t". The parametric value "t" is stored in the last index location of the specified double array. This value should not be changed. The dimension of the point to evaluate is p.length - 1. The result of the evaluation is placed in index locations 0 .. p.length - 2 (inclusive).
    The eval method should remain protected except for those curves that do no need any preparation to be done in the appendTo method.
  - getAlpha
```
public double getAlpha()
```
    Returns the value of alpha. The default value is 0.5.
    
    See Also:
    
    setAlpha(double)
  - setAlpha
```
public void setAlpha(double a)
```
    Sets the value of alpha.
    
    See Also:
    
    getAlpha()
  - getSampleLimit
```
public int getSampleLimit()
```
    Returns a value of 1.
  - appendTo
```
public void appendTo(com.macrofocus.high_d.parallelcoordinates.geometry.curve.MultiPath mp)
```
    The requirements for this curve are the group-iterator must be in-range and have a group size of at least 4. If these requirements are not met then this method returns quietly.
    
    Specified by:
    
    appendTo in class Curve
    
    See Also:
    
    MultiPath, BinaryCurveApproximationAlgorithm