Parallel Colt 0.7.2

## cern.jet.math.tdouble Class Bessel

```java.lang.Object cern.jet.math.tdouble.DoubleConstants cern.jet.math.tdouble.Bessel
```

`public class Besselextends DoubleConstants`

Bessel and Airy functions.

Method Summary
`static double` `i0(double x)`
Returns the modified Bessel function of order 0 of the argument.
`static double` `i0e(double x)`
Returns the exponentially scaled modified Bessel function of order 0 of the argument.
`static double` `i1(double x)`
Returns the modified Bessel function of order 1 of the argument.
`static double` `i1e(double x)`
Returns the exponentially scaled modified Bessel function of order 1 of the argument.
`static double` `j0(double x)`
Returns the Bessel function of the first kind of order 0 of the argument.
`static double` `j1(double x)`
Returns the Bessel function of the first kind of order 1 of the argument.
`static double` ```jn(int n, double x)```
Returns the Bessel function of the first kind of order n of the argument.
`static double` `k0(double x)`
Returns the modified Bessel function of the third kind of order 0 of the argument.
`static double` `k0e(double x)`
Returns the exponentially scaled modified Bessel function of the third kind of order 0 of the argument.
`static double` `k1(double x)`
Returns the modified Bessel function of the third kind of order 1 of the argument.
`static double` `k1e(double x)`
Returns the exponentially scaled modified Bessel function of the third kind of order 1 of the argument.
`static double` ```kn(int nn, double x)```
Returns the modified Bessel function of the third kind of order nn of the argument.
`static double` `y0(double x)`
Returns the Bessel function of the second kind of order 0 of the argument.
`static double` `y1(double x)`
Returns the Bessel function of the second kind of order 1 of the argument.
`static double` ```yn(int n, double x)```
Returns the Bessel function of the second kind of order n of the argument.

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

Method Detail

### i0

```public static double i0(double x)
throws ArithmeticException```
Returns the modified Bessel function of order 0 of the argument.

The function is defined as i0(x) = j0( ix ).

The range is partitioned into the two intervals [0,8] and (8, infinity). Chebyshev polynomial expansions are employed in each interval.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### i0e

```public static double i0e(double x)
throws ArithmeticException```
Returns the exponentially scaled modified Bessel function of order 0 of the argument.

The function is defined as i0e(x) = exp(-|x|) j0( ix ).

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### i1

```public static double i1(double x)
throws ArithmeticException```
Returns the modified Bessel function of order 1 of the argument.

The function is defined as i1(x) = -i j1( ix ).

The range is partitioned into the two intervals [0,8] and (8, infinity). Chebyshev polynomial expansions are employed in each interval.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### i1e

```public static double i1e(double x)
throws ArithmeticException```
Returns the exponentially scaled modified Bessel function of order 1 of the argument.

The function is defined as i1(x) = -i exp(-|x|) j1( ix ).

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### j0

```public static double j0(double x)
throws ArithmeticException```
Returns the Bessel function of the first kind of order 0 of the argument.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### j1

```public static double j1(double x)
throws ArithmeticException```
Returns the Bessel function of the first kind of order 1 of the argument.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### jn

```public static double jn(int n,
double x)
throws ArithmeticException```
Returns the Bessel function of the first kind of order n of the argument.

Parameters:
`n` - the order of the Bessel function.
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### k0

```public static double k0(double x)
throws ArithmeticException```
Returns the modified Bessel function of the third kind of order 0 of the argument.

The range is partitioned into the two intervals [0,8] and (8, infinity). Chebyshev polynomial expansions are employed in each interval.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### k0e

```public static double k0e(double x)
throws ArithmeticException```
Returns the exponentially scaled modified Bessel function of the third kind of order 0 of the argument.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### k1

```public static double k1(double x)
throws ArithmeticException```
Returns the modified Bessel function of the third kind of order 1 of the argument.

The range is partitioned into the two intervals [0,2] and (2, infinity). Chebyshev polynomial expansions are employed in each interval.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### k1e

```public static double k1e(double x)
throws ArithmeticException```
Returns the exponentially scaled modified Bessel function of the third kind of order 1 of the argument.

k1e(x) = exp(x) * k1(x).

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### kn

```public static double kn(int nn,
double x)
throws ArithmeticException```
Returns the modified Bessel function of the third kind of order nn of the argument.

The range is partitioned into the two intervals [0,9.55] and (9.55, infinity). An ascending power series is used in the low range, and an asymptotic expansion in the high range.

Parameters:
`nn` - the order of the Bessel function.
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### y0

```public static double y0(double x)
throws ArithmeticException```
Returns the Bessel function of the second kind of order 0 of the argument.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### y1

```public static double y1(double x)
throws ArithmeticException```
Returns the Bessel function of the second kind of order 1 of the argument.

Parameters:
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

### yn

```public static double yn(int n,
double x)
throws ArithmeticException```
Returns the Bessel function of the second kind of order n of the argument.

Parameters:
`n` - the order of the Bessel function.
`x` - the value to compute the bessel function of.
Throws:
`ArithmeticException`

Parallel Colt 0.7.2