de.unihalle.informatik.MiToBo.segmentation.levelset.core

Enum DeltaApproxHelper.ApproxVersion

java.lang.Object

java.lang.Enum<DeltaApproxHelper.ApproxVersion>

de.unihalle.informatik.MiToBo.segmentation.levelset.core.DeltaApproxHelper.ApproxVersion

All Implemented Interfaces:

Serializable, Comparable<DeltaApproxHelper.ApproxVersion>

Enclosing class:

DeltaApproxHelper

public static enum DeltaApproxHelper.ApproxVersion
extends Enum<DeltaApproxHelper.ApproxVersion>

Available approximations for the Heaviside function and its derivatives.

Enum Constant Summary

Enum Constants

Enum Constant and Description
VERSION_1 \begin{eqnarray*} H_{1,\epsilon}(x) = \hspace*{4cm} 1, & \text{if} \; x > \epsilon \\ 0, & \text{if} \; x < -\epsilon \\ \frac{1}{2} \cdot \left[1 + \frac{x}{\epsilon} + \frac{1}{\pi}\sin\left(\frac{\pi x}{\epsilon}\right)\right] , & \text{if} \; |x| \leq \epsilon \ \end{eqnarray*} \begin{eqnarray*} \delta_{1,\epsilon}(x) = H^\prime_{1,\epsilon}(x) = \hspace*{4cm} 0, & \text{if} \; |x| > \epsilon \\ \frac{1}{2\epsilon} \cdot \left[1 + \cos\left(\frac{\pi x}{\epsilon}\right)\right] , & \text{if} \; |x| \leq \epsilon \ \end{eqnarray*}
VERSION_2 \begin{eqnarray*} H_{2,\epsilon}(x) = \frac{1}{2} \cdot \left( 1 + \frac{2}{\pi} \text{atan} \left( \frac{x}{\epsilon} \right) \right) \end{eqnarray*} \begin{eqnarray*} \delta_{2,\epsilon}(x) = H^\prime_{2,\epsilon}(x) = \frac{1}{\pi} \cdot \left( \frac{\epsilon}{\epsilon^2+x^2} \right) \end{eqnarray*}

Method Summary

Modifier and Type	Method and Description
static DeltaApproxHelper.ApproxVersion	valueOf(String name) Returns the enum constant of this type with the specified name.
static DeltaApproxHelper.ApproxVersion[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

VERSION_1

public static final DeltaApproxHelper.ApproxVersion VERSION_1

\begin{eqnarray*} H_{1,\epsilon}(x) = \hspace*{4cm} 1, & \text{if} \; x > \epsilon \\ 0, & \text{if} \; x < -\epsilon \\ \frac{1}{2} \cdot \left[1 + \frac{x}{\epsilon} + \frac{1}{\pi}\sin\left(\frac{\pi x}{\epsilon}\right)\right] , & \text{if} \; |x| \leq \epsilon \ \end{eqnarray*} \begin{eqnarray*} \delta_{1,\epsilon}(x) = H^\prime_{1,\epsilon}(x) = \hspace*{4cm} 0, & \text{if} \; |x| > \epsilon \\ \frac{1}{2\epsilon} \cdot \left[1 + \cos\left(\frac{\pi x}{\epsilon}\right)\right] , & \text{if} \; |x| \leq \epsilon \ \end{eqnarray*}

VERSION_2

public static final DeltaApproxHelper.ApproxVersion VERSION_2

\begin{eqnarray*} H_{2,\epsilon}(x) = \frac{1}{2} \cdot \left( 1 + \frac{2}{\pi} \text{atan} \left( \frac{x}{\epsilon} \right) \right) \end{eqnarray*} \begin{eqnarray*} \delta_{2,\epsilon}(x) = H^\prime_{2,\epsilon}(x) = \frac{1}{\pi} \cdot \left( \frac{\epsilon}{\epsilon^2+x^2} \right) \end{eqnarray*}

Method Detail

values

public static DeltaApproxHelper.ApproxVersion[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (DeltaApproxHelper.ApproxVersion c : DeltaApproxHelper.ApproxVersion.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static DeltaApproxHelper.ApproxVersion valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null