MathUtils (patrimoine de base SIRIUS 4.11 API)

java.lang.Object
- fr.cnes.sirius.patrius.math.util.MathUtils

```
public final class MathUtils
extends Object
```
Miscellaneous utility functions.

Version:

$Id: MathUtils.java 18108 2017-10-04 06:45:27Z bignon $

See Also:

ArithmeticUtils, Precision, MathArrays

Field Summary

Fields
Modifier and Type	Field and Description
`static double`	`DEG_TO_RAD` π/180.
`static double`	`HALF_CIRCLE` 180.
`static double`	`HALF_PI` π/2.
`static double`	`RAD_TO_DEG` 180/π.
`static double`	`TWO_PI` 2 π.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`checkFinite(double x)` Check that the argument is a real number.
`static void`	`checkFinite(double[] val)` Check that all the elements are real numbers.
`static void`	`checkNotNull(Object o)` Checks that an object is not null.
`static void`	`checkNotNull(Object o, Localizable pattern, Object... args)` Checks that an object is not null.
`static byte`	`copySign(byte magnitude, byte sign)` Returns the first argument with the sign of the second argument.
`static int`	`copySign(int magnitude, int sign)` Returns the first argument with the sign of the second argument.
`static long`	`copySign(long magnitude, long sign)` Returns the first argument with the sign of the second argument.
`static double`	`findSmallestOffset(double nb, Double a, Double b)` Among 2 values, determines the smallest relative distance to a given number.
`static int`	`hash(double value)` Returns an integer hash code representing the given double value.
`static int`	`hash(double[] value)` Returns an integer hash code representing the given double array.
`static double`	`normalizeAngle(double a, double center)` Normalize an angle in a 2&pi wide interval around a center value.
`static double`	`reduce(double a, double period, double offset)` Reduce `\|a - offset\|` to the primary interval `[0, \|period\|)`.
`static double[]`	`solveQuadraticEquation(double aCoefficient, double bCoefficient, double cCoefficient)` Calculation of a quadratic equation (ax^2 + bx + c) and return the positive root
`static double`	`solveQuadraticEquationMaxRoot(double aCoefficient, double bCoefficient, double cCoefficient)` Calculation of a quadratic equation (ax^2 + bx + c) and return the positive root
`static double`	`solveQuadraticEquationMinRoot(double aCoefficient, double bCoefficient, double cCoefficient)` Calculation of a quadratic equation (ax^2 + bx + c) and return the positive root

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

- Field Detail
  - TWO_PI
```
public static final double TWO_PI
```
    2 π.
    
    Since:
    
    2.1
    
    See Also:
    
    Constant Field Values
  - HALF_PI
```
public static final double HALF_PI
```
    π/2.
    
    See Also:
    
    Constant Field Values
  - HALF_CIRCLE
```
public static final double HALF_CIRCLE
```
    180.
    
    See Also:
    
    Constant Field Values
  - DEG_TO_RAD
```
public static final double DEG_TO_RAD
```
    π/180.
    
    See Also:
    
    Constant Field Values
  - RAD_TO_DEG
```
public static final double RAD_TO_DEG
```
    180/π.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - hash
```
public static int hash(double value)
```
    Returns an integer hash code representing the given double value.
    
    Parameters:
    
    value - the value to be hashed
    
    Returns:
    
    the hash code
  - hash
```
public static int hash(double[] value)
```
    Returns an integer hash code representing the given double array.
    
    Parameters:
    
    value - the value to be hashed (may be null)
    
    Returns:
    
    the hash code
    
    Since:
    
    1.2
  - normalizeAngle
```
public static double normalizeAngle(double a,
                                    double center)
```
    Normalize an angle in a 2&pi wide interval around a center value.
    This method has three main uses:
    - normalize an angle between 0 and 2π:
      a = MathUtils.normalizeAngle(a, FastMath.PI);
    - normalize an angle between -π and +π
      a = MathUtils.normalizeAngle(a, 0.0);
    - compute the angle between two defining angular positions:
      angle = MathUtils.normalizeAngle(end, start) - start;
    Note that due to numerical accuracy and since π cannot be represented exactly, the result interval is closed, it cannot be half-closed as would be more satisfactory in a purely mathematical view.
    Parameters:
    
    a - angle to normalize
    
    center - center of the desired 2π interval for the result
    
    Returns:
    
    a-2kπ with integer k and center-π <= a-2kπ <= center+π
    
    Since:
    
    1.2
  - reduce
```
public static double reduce(double a,
                            double period,
                            double offset)
```
    Reduce |a - offset| to the primary interval [0, |period|).
    
    Specifically, the value returned is
    a - |period| * floor((a - offset) / |period|) - offset.
    
    If any of the parameters are NaN or infinite, the result is NaN.
    
    Parameters:
    
    a - Value to reduce.
    
    period - Period.
    
    offset - Value that will be mapped to 0.
    
    Returns:
    
    the value, within the interval [0 |period|), that corresponds to a.
  - copySign
```
public static byte copySign(byte magnitude,
                            byte sign)
```
    Returns the first argument with the sign of the second argument.
    
    Parameters:
    
    magnitude - Magnitude of the returned value.
    
    sign - Sign of the returned value.
    
    Returns:
    
    a value with magnitude equal to magnitude and with the same sign as the sign argument.
    
    Throws:
    
    MathArithmeticException - if magnitude == Byte.MIN_VALUE and sign >= 0.
  - copySign
```
public static int copySign(int magnitude,
                           int sign)
```
    Returns the first argument with the sign of the second argument.
    
    Parameters:
    
    magnitude - Magnitude of the returned value.
    
    sign - Sign of the returned value.
    
    Returns:
    
    a value with magnitude equal to magnitude and with the same sign as the sign argument.
    
    Throws:
    
    MathArithmeticException - if magnitude == Integer.MIN_VALUE and sign >= 0.
  - copySign
```
public static long copySign(long magnitude,
                            long sign)
```
    Returns the first argument with the sign of the second argument.
    
    Parameters:
    
    magnitude - Magnitude of the returned value.
    
    sign - Sign of the returned value.
    
    Returns:
    
    a value with magnitude equal to magnitude and with the same sign as the sign argument.
    
    Throws:
    
    MathArithmeticException - if magnitude == Long.MIN_VALUE and sign >= 0.
  - checkFinite
```
public static void checkFinite(double x)
```
    Check that the argument is a real number.
    
    Parameters:
    
    x - Argument.
    
    Throws:
    
    NotFiniteNumberException - if x is not a finite real number.
  - checkFinite
```
public static void checkFinite(double[] val)
```
    Check that all the elements are real numbers.
    
    Parameters:
    
    val - Arguments.
    
    Throws:
    
    NotFiniteNumberException - if any values of the array is not a finite real number.
  - checkNotNull
```
public static void checkNotNull(Object o,
                                Localizable pattern,
                                Object... args)
```
    Checks that an object is not null.
    
    Parameters:
    
    o - Object to be checked.
    
    pattern - Message pattern.
    
    args - Arguments to replace the placeholders in pattern.
    
    Throws:
    
    NullArgumentException - if o is null.
  - checkNotNull
```
public static void checkNotNull(Object o)
```
    Checks that an object is not null.
    
    Parameters:
    
    o - Object to be checked.
    
    Throws:
    
    NullArgumentException - if o is null.
  - solveQuadraticEquation
```
public static double[] solveQuadraticEquation(double aCoefficient,
                                              double bCoefficient,
                                              double cCoefficient)
```
    Calculation of a quadratic equation (ax^2 + bx + c) and return the positive root
    
    Parameters:
    
    aCoefficient - - a Coefficient
    
    bCoefficient - - b Coefficient
    
    cCoefficient - - c Coefficient
    
    Returns:
    
    the calculate roots (-c/b if a==0, exception if a==b==0)
  - solveQuadraticEquationMaxRoot
```
public static double solveQuadraticEquationMaxRoot(double aCoefficient,
                                                   double bCoefficient,
                                                   double cCoefficient)
```
    Calculation of a quadratic equation (ax^2 + bx + c) and return the positive root
    
    Parameters:
    
    aCoefficient - - a Coefficient
    
    bCoefficient - - b Coefficient
    
    cCoefficient - - c Coefficient
    
    Returns:
    
    the max value of the two calculated roots
  - solveQuadraticEquationMinRoot
```
public static double solveQuadraticEquationMinRoot(double aCoefficient,
                                                   double bCoefficient,
                                                   double cCoefficient)
```
    Calculation of a quadratic equation (ax^2 + bx + c) and return the positive root
    
    Parameters:
    
    aCoefficient - - a Coefficient
    
    bCoefficient - - b Coefficient
    
    cCoefficient - - c Coefficient
    
    Returns:
    
    the min value of the two calculated roots
  - findSmallestOffset
```
public static double findSmallestOffset(double nb,
                                        Double a,
                                        Double b)
```
    Among 2 values, determines the smallest relative distance to a given number. In case of equality, distance to a is returned.
    
    Parameters:
    
    nb - the given number
    
    a - the first value
    
    b - the second value
    
    Returns:
    
    the nearest value to the given number

Class MathUtils

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TWO_PI

HALF_PI

HALF_CIRCLE

DEG_TO_RAD

RAD_TO_DEG

Method Detail

hash

hash

normalizeAngle

reduce

copySign

copySign

copySign

checkFinite

checkFinite

checkNotNull

checkNotNull

solveQuadraticEquation

solveQuadraticEquationMaxRoot

solveQuadraticEquationMinRoot

findSmallestOffset