de.unihalle.informatik.MiToBo.apps.xylem

## Class MathHelper

• ```public final class MathHelper
extends Object```
• ### Field Summary

Fields
Modifier and Type Field and Description
`static double` `PI_HALF`
• ### Constructor Summary

Constructors
Modifier Constructor and Description
`private ` `MathHelper()`
• ### Method Summary

All Methods
Modifier and Type Method and Description
`static double` `acot(double value)`
Return the `arcus cotangens` of `value` in radian.
`static double` ```angleDiff360(double angleOne, double angleTwo)```
`static double` `calcMean(double[] values)`
Return the mean value of an array of double.
`static double` `calcMedian(double[] values)`
Returns the median value of an array of double.
`static double[]` `calcMinMax(double[] values)`
Returns the min and max value.
`static double` `calcVariance(double[] values)`
Returns the variance of an array of double.
`static double` `cot(double value)`
Return the `cotangens` of `value`.
`static Point2D.Double` ```point2DDiff(Point2D.Double pointOne, Point2D.Double pointTwo)```
Substract two `Point2D.Double `.
`static Point2D.Double` ```point2DSum(Point2D.Double pointOne, Point2D.Double pointTwo)```
Sums up two `Point2D.Double `.
`static Point2D.Double` `toCartesianAsPoint2D(double angleDegree)`
Converts an angle in degree to its corresponding in cartesian coordinates.
`static double[]` `toCartesianAsVector(double angleDegree)`
Converts an angle in degree to its correspondant in cartesian coordinates.
`static double` `toPositiveAngle360(double angle)`
Simple way to convert negative angles to 0-360 degree.
`static double[]` `unitVector(double[] vector)`
Return the unit vector of `vector`.
`static double[]` ```vectorDiff(double[] vecOne, double[] vecTwo)```
Subtract two vectors.
`static double` `vectorNorm(double[] vector)`
Returns the norm of a vector.
`static double[]` ```vectorSum(double[] vecOne, double[] vecTwo)```
Sums up two vectors.
• ### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`
• ### Field Detail

• #### PI_HALF

`public static final double PI_HALF`
Constant Field Values
• ### Constructor Detail

• #### MathHelper

`private MathHelper()`
• ### Method Detail

• #### acot

`public static final double acot(double value)`
Return the `arcus cotangens` of `value` in radian.

This function is implemented as described in "Teubner - Taschenbuch der Mathematik [Bronstein/Samendjajew]".

Parameters:
`value` - A rational floating point number.
Returns:
The `Arcuscotangens` of `value`.
• #### angleDiff360

```public static final double angleDiff360(double angleOne,
double angleTwo)```
Parameters:
`angleOne` -
`angleTwo` -
Returns:
• #### calcMean

`public static double calcMean(double[] values)`
Return the mean value of an array of double.

Parameters:
`values` -
Returns:
• #### calcMedian

`public static double calcMedian(double[] values)`
Returns the median value of an array of double.

Parameters:
`values` -
Returns:
• #### calcMinMax

`public static double[] calcMinMax(double[] values)`
Returns the min and max value.

Parameters:
`values` -
Returns:
• #### calcVariance

`public static double calcVariance(double[] values)`
Returns the variance of an array of double.

Parameters:
`values` -
Returns:
• #### cot

`public static final double cot(double value)`
Return the `cotangens` of `value`. In case of `0` the returned value is `not a number` - the tangens function is not defined for zero -> 1/Infinty is not a number.

Parameters:
`value` - The argument of the cotangens function.
Returns:
The result of the cotangens function.
• #### point2DDiff

```public static final Point2D.Double point2DDiff(Point2D.Double pointOne,
Point2D.Double pointTwo)```
Substract two `Point2D.Double `.

Parameters:
`pointOne` -
`pointTwo` -
Returns:
• #### point2DSum

```public static final Point2D.Double point2DSum(Point2D.Double pointOne,
Point2D.Double pointTwo)```
Sums up two `Point2D.Double `.

Parameters:
`pointOne` -
`pointTwo` -
Returns:
• #### toCartesianAsPoint2D

`public static final Point2D.Double toCartesianAsPoint2D(double angleDegree)`
Converts an angle in degree to its corresponding in cartesian coordinates.

Parameters:
`angleDegree` - An angle in degree.
Returns:
A `Point2D.Double ` containing the coordinate in cartesian coordinate system
• #### toCartesianAsVector

`public static final double[] toCartesianAsVector(double angleDegree)`
Converts an angle in degree to its correspondant in cartesian coordinates.

Parameters:
`angleDegree` - An angle between 0 and 359 degree.
Returns:
An array with the `x ` and `y ` cartesian coordinate.
• #### toPositiveAngle360

`public static final double toPositiveAngle360(double angle)`
Simple way to convert negative angles to 0-360 degree.

Parameters:
`angle` - An angle in the range of [-360,360]
Returns:
• #### vectorDiff

```public static double[] vectorDiff(double[] vecOne,
double[] vecTwo)```
Subtract two vectors.

Parameters:
`vecOne` -
`vecTwo` -
Returns:
• #### vectorNorm

`public static double vectorNorm(double[] vector)`
Returns the norm of a vector.

Parameters:
`vector` -
Returns:
• #### unitVector

`public static double[] unitVector(double[] vector)`
Return the unit vector of `vector`.

Parameters:
`vector` -
Returns:
• #### vectorSum

```public static final double[] vectorSum(double[] vecOne,
double[] vecTwo)```
Sums up two vectors.

Parameters:
`vecOne` -
`vecTwo` -
Returns: