Movatterモバイル変換

j0(3p) — Linux manual page

J0(3P)                  POSIX Programmer's ManualJ0(3P)

PROLOG        top

       This manual page is part of the POSIX Programmer's Manual.  The       Linux implementation of this interface may differ (consult the       corresponding Linux manual page for details of Linux behavior), or       the interface may not be implemented on Linux.

NAME        top

       j0, j1, jn — Bessel functions of the first kind

SYNOPSIS        top

       #include <math.h>       double j0(doublex);       double j1(doublex);       double jn(intn, doublex);

DESCRIPTION        top

       Thej0(),j1(), andjn() functions shall compute Bessel functions       ofx of the first kind of orders 0, 1, andn, respectively.       An application wishing to check for error situations should seterrno to zero and callfeclearexcept(FE_ALL_EXCEPT) before calling       these functions. On return, iferrno is non-zero orfetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |       FE_UNDERFLOW) is non-zero, an error has occurred.

RETURN VALUE        top

       Upon successful completion, these functions shall return the       relevant Bessel value ofx of the first kind.       If thex argument is too large in magnitude, or the correct result       would cause underflow, 0 shall be returned and a range error may       occur.       Ifx is NaN, a NaN shall be returned.

ERRORS        top

       These functions may fail if:       Range Error The value ofx was too large in magnitude, or an                   underflow occurred.                   If the integer expression (math_errhandling &                   MATH_ERRNO) is non-zero, thenerrno shall be set to[ERANGE].  If the integer expression (math_errhandling                   & MATH_ERREXCEPT) is non-zero, then the underflow                   floating-point exception shall be raised.       No other errors shall occur.The following sections are informative.

EXAMPLES        top

       None.

APPLICATION USAGE        top

       On error, the expressions (math_errhandling & MATH_ERRNO) and       (math_errhandling & MATH_ERREXCEPT) are independent of each other,       but at least one of them must be non-zero.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

feclearexcept(3p),fetestexcept(3p),isnan(3p),y0(3p)       The Base Definitions volume of POSIX.1‐2017,Section 4.20,Treatment of Error Conditions for Mathematical Functions,math.h(0p)

COPYRIGHT        top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 by the Institute of Electrical and Electronics Engineers,       Inc and The Open Group.  In the event of any discrepancy between       this version and the original IEEE and The Open Group Standard,       the original IEEE and The Open Group Standard is the referee       document. The original Standard can be obtained online athttp://www.opengroup.org/unix/online.html .       Any typographical or formatting errors that appear in this page       are most likely to have been introduced during the conversion of       the source files to man page format. To report such errors, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017J0(3P)

Pages that refer to this page:math.h(0p), y0(3p)

HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH.