SpecialMathFunction (NetCDF-Java 4.2 Public and Private API)

java.lang.Object
- ucar.unidata.util.SpecialMathFunction

```
public final class SpecialMathFunction
extends java.lang.Object
```
This class contains physical constants and special functions not found in the java.lang.Math class. Like the java.lang.Math class this class is final and cannot be subclassed. All physical constants are in cgs units.
NOTE: These special functions do not necessarily use the fastest or most accurate algorithms.

Author:

Leigh Brookshaw

Field Summary

Fields
Modifier and Type	Field and Description
`static double`	`AU` Astronomical Unit (radius of the Earth's orbit).
`static double`	`AVOGADRO` Avogadro Number.
`static double`	`BOLTZMAN` Boltzman Constant.
`static double`	`ECHARGE` Elementary Charge.
`static double`	`EMASS` Electron Mass.
`static double`	`GASCONSTANT` Gas Constant.
`static double`	`GRAV` Gravitational Constant.
`static double`	`GRAVACC` Gravitational Acceleration at the Earths surface.
`static double`	`LIGHTSPEED` Speed of Light in a Vacuum.
`static double`	`PLANCK` Planck constant.
`static double`	`PMASS` Proton Mass.
`static double`	`SOLARFLUX` Solar Flux.
`static double`	`SOLARLUM` Solar Luminosity.
`static double`	`SOLARMASS` Solar Mass.
`static double`	`SOLARRADIUS` Solar Radius.
`static double`	`STEFANBOLTZ` Stefan-Boltzman Constant.

Method Summary

Methods
Modifier and Type	Method and Description
`static double`	`acosh(double x)`
`static double`	`asinh(double xx)` Compute the hyperbolic arc sine
`static double`	`atanh(double x)` Compute the hyperbolic arc tangent
`static double`	`chisq(double df, double x)` Returns the area under the left hand tail (from 0 to x) of the Chi square probability density function with v degrees of freedom.
`static double`	`chisqc(double df, double x)` Returns the area under the right hand tail (from x to infinity) of the Chi square probability density function with v degrees of freedom:
`static double`	`cosh(double x)`
`static double`	`erf(double x)`
`static double`	`erfc(double a)`
`static double`	`fac(double x)`
`static int`	`fac(int j)` Compute the factorial of the argument
`static double`	`gamma(double x)`
`static double`	`ibeta(double aa, double bb, double xx)`
`static double`	`igam(double a, double x)`
`static double`	`igamc(double a, double x)`
`static double`	`j0(double x)`
`static double`	`j1(double x)`
`static double`	`jn(int n, double x)`
`static double`	`log10(double x)` Get the log base 10 of a number
`static double`	`log2(double x)` Get the log base 2 of a number
`static double`	`normal(double a)`
`static double`	`poisson(int k, double x)` Returns the sum of the first k terms of the Poisson distribution.
`static double`	`poissonc(int k, double x)` Returns the sum of the terms k+1 to infinity of the Poisson distribution.
`static double`	`sinh(double x)`
`static double`	`tanh(double x)`
`static double`	`y0(double x)`
`static double`	`y1(double x)`
`static double`	`yn(int n, double x)`

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

- Field Detail
  - BOLTZMAN
```
public static final double BOLTZMAN
```
    Boltzman Constant. Units erg/deg(K)
    
    See Also:
    Constant Field Values
  - ECHARGE
```
public static final double ECHARGE
```
    Elementary Charge. Units statcoulomb
    
    See Also:
    Constant Field Values
  - EMASS
```
public static final double EMASS
```
    Electron Mass. Units g
    
    See Also:
    Constant Field Values
  - PMASS
```
public static final double PMASS
```
    Proton Mass. Units g
    
    See Also:
    Constant Field Values
  - GRAV
```
public static final double GRAV
```
    Gravitational Constant. Units dyne-cm^2/g^2
    
    See Also:
    Constant Field Values
  - PLANCK
```
public static final double PLANCK
```
    Planck constant. Units erg-sec
    
    See Also:
    Constant Field Values
  - LIGHTSPEED
```
public static final double LIGHTSPEED
```
    Speed of Light in a Vacuum. Units cm/sec
    
    See Also:
    Constant Field Values
  - STEFANBOLTZ
```
public static final double STEFANBOLTZ
```
    Stefan-Boltzman Constant. Units erg/cm^2-sec-deg^4
    
    See Also:
    Constant Field Values
  - AVOGADRO
```
public static final double AVOGADRO
```
    Avogadro Number. Units 1/mol
    
    See Also:
    Constant Field Values
  - GASCONSTANT
```
public static final double GASCONSTANT
```
    Gas Constant. Units erg/deg-mol
    
    See Also:
    Constant Field Values
  - GRAVACC
```
public static final double GRAVACC
```
    Gravitational Acceleration at the Earths surface. Units cm/sec^2
    
    See Also:
    Constant Field Values
  - SOLARMASS
```
public static final double SOLARMASS
```
    Solar Mass. Units g
    
    See Also:
    Constant Field Values
  - SOLARRADIUS
```
public static final double SOLARRADIUS
```
    Solar Radius. Units cm
    
    See Also:
    Constant Field Values
  - SOLARLUM
```
public static final double SOLARLUM
```
    Solar Luminosity. Units erg/sec
    
    See Also:
    Constant Field Values
  - SOLARFLUX
```
public static final double SOLARFLUX
```
    Solar Flux. Units erg/cm^2-sec
    
    See Also:
    Constant Field Values
  - AU
```
public static final double AU
```
    Astronomical Unit (radius of the Earth's orbit). Units cm
    
    See Also:
    Constant Field Values
- Method Detail
  - log10
```
public static double log10(double x)
                    throws java.lang.ArithmeticException
```
    Get the log base 10 of a number
    
    Parameters:
    x - a double value
    
    Returns:
    The log₁₀ of x
    
    Throws:
    
    java.lang.ArithmeticException - if (x < 0)
  - log2
```
public static double log2(double x)
                   throws java.lang.ArithmeticException
```
    Get the log base 2 of a number
    
    Parameters:
    x - a double value
    
    Returns:
    The log₂ of x
    
    Throws:
    
    java.lang.ArithmeticException - if (x < 0)
  - cosh
```
public static double cosh(double x)
                   throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the hyperbolic cosine of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - sinh
```
public static double sinh(double x)
                   throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the hyperbolic sine of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - tanh
```
public static double tanh(double x)
                   throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the hyperbolic tangent of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - acosh
```
public static double acosh(double x)
                    throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the hyperbolic arc cosine of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - asinh
```
public static double asinh(double xx)
                    throws java.lang.ArithmeticException
```
    Compute the hyperbolic arc sine
    
    Parameters:
    xx - a double value
    
    Returns:
    the hyperbolic arc sine of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - atanh
```
public static double atanh(double x)
                    throws java.lang.ArithmeticException
```
    Compute the hyperbolic arc tangent
    
    Parameters:
    x - a double value
    
    Returns:
    the hyperbolic arc tangent of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - j0
```
public static double j0(double x)
                 throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the Bessel function of order 0 of the argument.
    
    Throws:
    
    java.lang.ArithmeticException
  - j1
```
public static double j1(double x)
                 throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the Bessel function of order 1 of the argument.
    
    Throws:
    
    java.lang.ArithmeticException
  - jn
```
public static double jn(int n,
        double x)
                 throws java.lang.ArithmeticException
```
    Parameters:
    n - integer order
    x - a double value
    
    Returns:
    the Bessel function of order n of the argument.
    
    Throws:
    
    java.lang.ArithmeticException
  - y0
```
public static double y0(double x)
                 throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the Bessel function of the second kind, of order 0 of the argument.
    
    Throws:
    
    java.lang.ArithmeticException
  - y1
```
public static double y1(double x)
                 throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the Bessel function of the second kind, of order 1 of the argument.
    
    Throws:
    
    java.lang.ArithmeticException
  - yn
```
public static double yn(int n,
        double x)
                 throws java.lang.ArithmeticException
```
    Parameters:
    n - integer order
    x - a double value
    
    Returns:
    the Bessel function of the second kind, of order n of the argument.
    
    Throws:
    
    java.lang.ArithmeticException
  - fac
```
public static double fac(double x)
                  throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the factorial of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - fac
```
public static int fac(int j)
               throws java.lang.ArithmeticException
```
    Compute the factorial of the argument
    
    Parameters:
    j - an integer value
    
    Returns:
    the factorial of the argument
    
    Throws:
    
    java.lang.ArithmeticException
  - gamma
```
public static double gamma(double x)
                    throws java.lang.ArithmeticException
```
    Parameters:
    x - a double value
    
    Returns:
    the Gamma function of the value.
    Converted to Java from
    Cephes Math Library Release 2.2: July, 1992
    Copyright 1984, 1987, 1989, 1992 by Stephen L. Moshier
    Direct inquiries to 30 Frost Street, Cambridge, MA 02140
    
    Throws:
    
    java.lang.ArithmeticException
  - igamc
```
public static double igamc(double a,
           double x)
                    throws java.lang.ArithmeticException
```
    Parameters:
    a - double value
    x - double value
    
    Returns:
    the Complemented Incomplete Gamma function.
    Converted to Java from
    Cephes Math Library Release 2.2: July, 1992
    Copyright 1984, 1987, 1989, 1992 by Stephen L. Moshier
    Direct inquiries to 30 Frost Street, Cambridge, MA 02140
    
    Throws:
    
    java.lang.ArithmeticException
  - igam
    
    public static double igam(double a, double x) throws java.lang.ArithmeticException
    
    Parameters:
    a - double value
    x - double value
    
    Returns:
    the Incomplete Gamma function.
    Converted to Java from
    Cephes Math Library Release 2.2: July, 1992
    Copyright 1984, 1987, 1989, 1992 by Stephen L. Moshier
    Direct inquiries to 30 Frost Street, Cambridge, MA 02140
    
    Throws:
    
    java.lang.ArithmeticException
  chisq
  
  public static double chisq(double df, double x) throws java.lang.ArithmeticException
  
  Returns the area under the left hand tail (from 0 to x) of the Chi square probability density function with v degrees of freedom.
  
  Parameters:
  df - degrees of freedom
  x - double value
  
  Returns:
  the Chi-Square function.
  
  Throws:
  
  java.lang.ArithmeticException
  
  chisqc
  
  public static double chisqc(double df, double x) throws java.lang.ArithmeticException
  
  Returns the area under the right hand tail (from x to infinity) of the Chi square probability density function with v degrees of freedom:
  
  Parameters:
  df - degrees of freedom
  x - double value
  
  Returns:
  the Chi-Square function.
  
  Throws:
  
  java.lang.ArithmeticException
  
  poisson
  
  public static double poisson(int k, double x) throws java.lang.ArithmeticException
  
  Returns the sum of the first k terms of the Poisson distribution.
  
  Parameters:
  k - number of terms
  x - double value
  
  Returns:
  _more_
  
  Throws:
  
  java.lang.ArithmeticException
  
  poissonc
  
  public static double poissonc(int k, double x) throws java.lang.ArithmeticException
  
  Returns the sum of the terms k+1 to infinity of the Poisson distribution.
  
  Parameters:
  k - start
  x - double value
  
  Returns:
  _more_
  
  Throws:
  
  java.lang.ArithmeticException
  
  normal
  
  public static double normal(double a) throws java.lang.ArithmeticException
  
  Parameters:
  a - double value
  
  Returns:
  The area under the Gaussian probability density function, integrated from minus infinity to x:
  
  Throws:
  
  java.lang.ArithmeticException
  
  erfc
  
  public static double erfc(double a) throws java.lang.ArithmeticException
  
  Parameters:
  a - double value
  
  Returns:
  The complementary Error function
  Converted to Java from
  Cephes Math Library Release 2.2: July, 1992
  Copyright 1984, 1987, 1989, 1992 by Stephen L. Moshier
  Direct inquiries to 30 Frost Street, Cambridge, MA 02140
  
  Throws:
  
  java.lang.ArithmeticException
  
  erf
  
  public static double erf(double x) throws java.lang.ArithmeticException
  
  Parameters:
  x - double value
  
  Returns:
  The Error function
  Converted to Java from
  Cephes Math Library Release 2.2: July, 1992
  Copyright 1984, 1987, 1989, 1992 by Stephen L. Moshier
  Direct inquiries to 30 Frost Street, Cambridge, MA 02140
  
  Throws:
  
  java.lang.ArithmeticException
  
  ibeta
  
  public static double ibeta(double aa, double bb, double xx) throws java.lang.ArithmeticException
  
  Parameters:
  aa - double value
  bb - double value
  xx - double value
  
  Returns:
  The Incomplete Beta Function evaluated from zero to xx.
  Converted to Java from
  Cephes Math Library Release 2.3: July, 1995
  Copyright 1984, 1995 by Stephen L. Moshier
  Direct inquiries to 30 Frost Street, Cambridge, MA 02140
  
  Throws:
  
  java.lang.ArithmeticException

Class SpecialMathFunction

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

BOLTZMAN

ECHARGE

EMASS

PMASS

GRAV

PLANCK

LIGHTSPEED

STEFANBOLTZ

AVOGADRO

GASCONSTANT

GRAVACC

SOLARMASS

SOLARRADIUS

SOLARLUM

SOLARFLUX

AU

Method Detail

log10

log2

cosh

sinh

tanh

acosh

asinh

atanh

j0

j1

jn

y0

y1

yn

fac

fac

gamma

igamc

igam

chisq

chisqc

poisson

poissonc

normal

erfc

erf

ibeta