Manpages - j0.3

j0, j0f, j0l, j1, j1f, j1l, jn, jnf, jnl - Bessel functions of the first kind

  #include <math.h>

  double j0(double x);
  double j1(double x);
  double jn(int n, double x);

  float j0f(float x);
  float j1f(float x);
  float jnf(int n, float x);

  long double j0l(long double x);
  long double j1l(long double x);
  long double jnl(int n, long double x);

Link with -lm.

Feature Test Macro Requirements for glibc (see *feature_test_macros*(7)):

*j0*(), *j1*(), *jn*():

      _XOPEN_SOURCE
          || /* Since glibc 2.19: */ _DEFAULT_SOURCE
          || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

*j0f*(), *j0l*(), *j1f*(), *j1l*(), *jnf*(), *jnl*():

      _XOPEN_SOURCE >= 600
          || (_ISOC99_SOURCE && _XOPEN_SOURCE)
          || /* Since glibc 2.19: */ _DEFAULT_SOURCE
          || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

The *j0*() and *j1*() functions return Bessel functions of x of the first kind of orders 0 and 1, respectively. The *jn*() function returns the Bessel function of x of the first kind of order n.

The *j0f*(), *j1f*(), and *jnf*(), functions are versions that take and return float values. The *j0l*(), *j1l*(), and *jnl*() functions are versions that take and return long double values.

On success, these functions return the appropriate Bessel value of the first kind for x.

If x is a NaN, a NaN is returned.

If x is too large in magnitude, or the result underflows, a range error occurs, and the return value is 0.

See *math_error*(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

• Range error: result underflow, or x is too large in magnitude :: errno is set to ERANGE.

These functions do not raise exceptions for *fetestexcept*(3).

For an explanation of the terms used in this section, see *attributes*(7).

The functions returning double conform to SVr4, 4.3BSD, POSIX.1-2001, and POSIX.1-2008. The others are nonstandard functions that also exist on the BSDs.

There are errors of up to 2e-16 in the values returned by *j0*(), *j1*(), and *jn*() for values of x between -8 and 8.

*y0*(3)

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