geomss.geom.cst

Class CSTShapeFunction

java.lang.Object

geomss.geom.cst.CSTShapeFunction

All Implemented Interfaces:

j2me.io.Serializable, java.lang.Cloneable, javolution.lang.Immutable, javolution.lang.ValueType, javolution.xml.XMLSerializable

public final class CSTShapeFunction
extends java.lang.Object
implements java.lang.Cloneable, javolution.xml.XMLSerializable, javolution.lang.ValueType

A generic Class-Shape-Transform (CST) shape function implementation.

Modified by: Joseph A. Huwaldt

Version:

January 8, 2016

Author:

Joseph A. Huwaldt Date: March 14, 2014

Method Summary

Modifier and Type	Method and Description
CSTShapeFunction	copy() Returns a copy of this CSTShapeFunction instance allocated by the calling thread (possibly on the stack).
boolean	equals(java.lang.Object obj) Compares this CSTShapeFunction against the specified object for strict equality (same values).
Point	get2DPoint(double s) Return a 2D point that represents the value of this shape function at the specified parametric position: (s,getValue(s)).
BasicNurbsCurve	getBasisFunction() Return the basis function for this shape function.
double[]	getCoefficients() Return the array of Bernstein Polynomial coefficients for this shape function.
double[]	getDerivatives(double s, int grade) Calculate all the derivatives from 0 to grade with respect to parametric distance on the shape function for the given parametric distance along the shape function, d^{grade}p(s)/d^{grade}s.
int	getOrder() Return the order of this shape function.
double	getValue(double s) Return the value of this shape function at the specified parametric location.
int	hashCode() Returns the hash code for this object.
boolean	isValid() Return true if this shape function contains valid and finite numerical components.
static CSTShapeFunction	newInstance(int order, double... Acoefs) Construct a new shape function of the specified order from the specified list of Bernstein Polynomial coefficients.
static CSTShapeFunction	valueOf(NurbsCurve bfCrv) Construct a new shape function from the specified 1D basis function Bezier curve.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Method Detail

newInstance

public static CSTShapeFunction newInstance(int order,
                                           double... Acoefs)

Construct a new shape function of the specified order from the specified list of Bernstein Polynomial coefficients.

Parameters:

order - The order of the shape function to return.

Acoefs - The coefficients of the Bernstein Polynomial used to construct the shape function. If more than "order" coefficients are provided then the additional coefficients are ignored. May not be null.

Returns:

A new shape function of the specified order from the specified list of Bernstein Polynomial coefficients.

valueOf

public static CSTShapeFunction valueOf(NurbsCurve bfCrv)

Construct a new shape function from the specified 1D basis function Bezier curve.

Parameters:

bfCrv - The 1D basis function Bezier curve used to define this shape function. May not be null.

Returns:

A new shape function based on the specified 1D basis function Bezier curve.

getOrder

public int getOrder()

Return the order of this shape function.

Returns:

order of shape function (degree + 1)

See Also:

getCoefficients()

getBasisFunction

public BasicNurbsCurve getBasisFunction()

Return the basis function for this shape function. The returned NURBS curve will always represent a 1D Bezier curve.

Returns:

The basis function for this shape function.

See Also:

getCoefficients()

getValue

public double getValue(double s)

Return the value of this shape function at the specified parametric location.

Parameters:

s - The parametric distance along the curve to calculate the value of this shape function at.

Returns:

The value of this shape function at the specified parametric location.

get2DPoint

public Point get2DPoint(double s)

Return a 2D point that represents the value of this shape function at the specified parametric position: (s,getValue(s)).

Parameters:

s - The parametric distance along the curve to calculate the value of this shape function at.

Returns:

A 2D point that represents the value of this shape function at the specified parametric position: P(s) = getValue(s).

getDerivatives

public double[] getDerivatives(double s,
                               int grade)

Calculate all the derivatives from 0 to grade with respect to parametric distance on the shape function for the given parametric distance along the shape function, d^{grade}p(s)/d^{grade}s.

Example:
1st derivative (grade = 1), this returns [p(s), dp(s)/ds];
2nd derivative (grade = 2), this returns [p(s), dp(s)/ds, d^2p(s)/d^2s]; etc.

Parameters:

s - Parametric distance to calculate derivatives for (0.0 to 1.0 inclusive).

grade - The maximum grade to calculate the derivatives for (1=1st derivative, 2=2nd derivative, etc)

Returns:

An array of derivatives up to the specified grade of the shape function at the specified parametric position. The returned array was allocated using javolution.context.ArrayFactory.DOUBLES_FACTORY, could be longer than the number of derivatives requested, and could be recycled by the user when no longer needed.

Throws:

java.lang.IllegalArgumentException - if the grade is < 0.

getCoefficients

public double[] getCoefficients()

Return the array of Bernstein Polynomial coefficients for this shape function. The array will have a length of the order of the polynomial.

Returns:

The array of Bernstein Polynomial coefficients for this shape function.

See Also:

getOrder(), getBasisFunction()

isValid

public boolean isValid()

Return true if this shape function contains valid and finite numerical components. A value of false will be returned if any of the values are NaN or Inf.

Returns:

true if this shape function contains valid and finite numerical values.

equals

public boolean equals(java.lang.Object obj)

Compares this CSTShapeFunction against the specified object for strict equality (same values).

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to compare with.

Returns:

true if this object is identical to that object; false otherwise.

hashCode

public int hashCode()

Returns the hash code for this object.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code value.

copy

public CSTShapeFunction copy()

Returns a copy of this CSTShapeFunction instance allocated by the calling thread (possibly on the stack).

Specified by:

copy in interface javolution.lang.ValueType

Returns:

an identical and independent copy of this object.