2004-11-03 13:51:07 +00:00
|
|
|
.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
|
|
|
|
.\" Distributed under GPL, 2002-07-27 Walter Harms
|
|
|
|
.\" This was done with the help of the glibc manual.
|
|
|
|
.\"
|
|
|
|
.\" 2004-10-31, aeb, corrected
|
2008-08-07 06:57:15 +00:00
|
|
|
.TH FPCLASSIFY 3 2008-08-07 "" "Linux Programmer's Manual"
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH NAME
|
2007-06-14 06:12:44 +00:00
|
|
|
fpclassify, isfinite, isnormal, isnan, isinf \- floating-point
|
|
|
|
classification macros
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH SYNOPSIS
|
|
|
|
.nf
|
|
|
|
.B #include <math.h>
|
|
|
|
.sp
|
|
|
|
.BI "int fpclassify(" x );
|
|
|
|
.sp
|
|
|
|
.BI "int isfinite(" x );
|
|
|
|
.sp
|
|
|
|
.BI "int isnormal(" x );
|
|
|
|
.sp
|
|
|
|
.BI "int isnan(" x );
|
|
|
|
.sp
|
|
|
|
.BI "int isinf(" x );
|
|
|
|
.fi
|
2004-11-16 11:01:14 +00:00
|
|
|
.sp
|
2007-07-08 12:11:40 +00:00
|
|
|
Link with \fI\-lm\fP.
|
|
|
|
.sp
|
|
|
|
.in -4n
|
|
|
|
Feature Test Macro Requirements for glibc (see
|
|
|
|
.BR feature_test_macros (7)):
|
|
|
|
.in
|
|
|
|
.sp
|
|
|
|
.\" I haven't fully grokked the source to determine the FTM requirements;
|
|
|
|
.\" in part, the following has been tested by experiment.
|
|
|
|
.ad l
|
|
|
|
.BR fpclassify (),
|
|
|
|
.BR isfinite (),
|
|
|
|
.BR isnormal ():
|
|
|
|
_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
|
|
|
|
.I cc\ -std=c99
|
|
|
|
.br
|
|
|
|
.BR isnan ():
|
|
|
|
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE; or
|
|
|
|
.I cc\ -std=c99
|
|
|
|
.br
|
|
|
|
.BR isinf ():
|
|
|
|
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
|
|
|
|
.I cc\ -std=c99
|
|
|
|
.ad b
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH DESCRIPTION
|
|
|
|
Floating point numbers can have special values, such as
|
2007-04-24 16:44:51 +00:00
|
|
|
infinite or NaN.
|
|
|
|
With the macro
|
2007-04-12 22:42:49 +00:00
|
|
|
.BI fpclassify( x )
|
2004-11-03 13:51:07 +00:00
|
|
|
you can find out what type
|
|
|
|
.I x
|
2007-04-24 16:44:51 +00:00
|
|
|
is.
|
|
|
|
The macro takes any floating-point expression as argument.
|
2007-04-12 22:42:49 +00:00
|
|
|
The result is one of the following values:
|
2008-08-01 05:26:19 +00:00
|
|
|
.TP 14
|
2007-12-16 13:29:10 +00:00
|
|
|
.B FP_NAN
|
2004-11-03 13:51:07 +00:00
|
|
|
.I x
|
|
|
|
is "Not a Number".
|
|
|
|
.TP
|
2007-12-16 13:29:10 +00:00
|
|
|
.B FP_INFINITE
|
2004-11-03 13:51:07 +00:00
|
|
|
.I x
|
2008-07-25 20:25:56 +00:00
|
|
|
is either positive infinity or negative infinity.
|
2007-04-12 22:42:49 +00:00
|
|
|
.TP
|
2007-12-16 13:29:10 +00:00
|
|
|
.B FP_ZERO
|
2004-11-03 13:51:07 +00:00
|
|
|
.I x
|
|
|
|
is zero.
|
|
|
|
.TP
|
2007-12-16 13:29:10 +00:00
|
|
|
.B FP_SUBNORMAL
|
2004-11-03 13:51:07 +00:00
|
|
|
.I x
|
|
|
|
is too small to be represented in normalized format.
|
|
|
|
.TP
|
2007-12-16 13:29:10 +00:00
|
|
|
.B FP_NORMAL
|
2006-04-21 19:01:43 +00:00
|
|
|
if nothing of the above is correct then it must be a
|
2004-11-03 13:51:07 +00:00
|
|
|
normal floating-point number.
|
|
|
|
.LP
|
|
|
|
The other macros provide a short answer to some standard questions.
|
2008-08-01 05:26:19 +00:00
|
|
|
.TP 14
|
2004-11-03 13:51:07 +00:00
|
|
|
.BI isfinite( x )
|
intro.1, time.1, adjtimex.2, capget.2, eventfd.2, fcntl.2, getrlimit.2, getsockopt.2, gettimeofday.2, intro.2, ioctl_list.2, ioperm.2, mlock.2, pivot_root.2, poll.2, prctl.2, ptrace.2, sched_setscheduler.2, select_tut.2, semget.2, sigaltstack.2, signalfd.2, sysctl.2, timer_settime.2, timerfd_create.2, wait.2, CPU_SET.3, argz_add.3, assert_perror.3, atexit.3, backtrace.3, bcmp.3, clearenv.3, ctime.3, dl_iterate_phdr.3, dlopen.3, ecvt.3, errno.3, error.3, ether_aton.3, exit.3, fenv.3, ferror.3, finite.3, flockfile.3, fnmatch.3, fpathconf.3, fpclassify.3, ftime.3, ftok.3, ftw.3, fwide.3, getaddrinfo.3, gethostbyname.3, getlogin.3, getnameinfo.3, getnetent.3, getopt.3, getprotoent.3, getrpcent.3, getservent.3, glob.3, hsearch.3, inet.3, isalpha.3, iswalnum.3, iswalpha.3, iswblank.3, iswcntrl.3, iswctype.3, iswdigit.3, iswgraph.3, iswlower.3, iswprint.3, iswpunct.3, iswspace.3, iswupper.3, iswxdigit.3, longjmp.3, lsearch.3, malloc.3, matherr.3, mblen.3, mbsinit.3, mbtowc.3, on_exit.3, printf.3, pthread_attr_init.3, pthread_attr_setaffinity_np.3, pthread_attr_setdetachstate.3, pthread_attr_setguardsize.3, pthread_attr_setinheritsched.3, pthread_attr_setschedparam.3, pthread_attr_setschedpolicy.3, pthread_attr_setscope.3, pthread_attr_setstack.3, pthread_attr_setstackaddr.3, pthread_attr_setstacksize.3, pthread_cancel.3, pthread_cleanup_push.3, pthread_equal.3, pthread_getattr_np.3, pthread_getcpuclockid.3, pthread_setaffinity_np.3, pthread_setcancelstate.3, pthread_setconcurrency.3, pthread_setschedparam.3, pthread_setschedprio.3, ptsname.3, putenv.3, putgrent.3, raise.3, rcmd.3, regex.3, rexec.3, rpc.3, rpmatch.3, rtnetlink.3, scandir.3, sem_init.3, setaliasent.3, setbuf.3, setenv.3, setjmp.3, signbit.3, stdio_ext.3, strtod.3, strtol.3, strtoul.3, system.3, termios.3, timeradd.3, tzset.3, ualarm.3, wctomb.3, xdr.3, st.4, tty_ioctl.4, core.5, elf.5, proc.5, bootparam.7, capabilities.7, icmp.7, ip.7, ipv6.7, math_error.7, mdoc.samples.7, mq_overview.7, pthreads.7, raw.7, regex.7, socket.7, tcp.7, tzselect.8: Global fix: s/non-zero/nonzero/
The tendency in English, as prescribed in style guides like
Chicago MoS, is towards removing hyphens after prefixes
like "non-" etc.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-01-16 16:40:55 +00:00
|
|
|
returns a nonzero value if
|
2004-11-03 13:51:07 +00:00
|
|
|
.br
|
|
|
|
(fpclassify(x) != FP_NAN && fpclassify(x) != FP_INFINITE)
|
|
|
|
.TP
|
|
|
|
.BI isnormal( x )
|
intro.1, time.1, adjtimex.2, capget.2, eventfd.2, fcntl.2, getrlimit.2, getsockopt.2, gettimeofday.2, intro.2, ioctl_list.2, ioperm.2, mlock.2, pivot_root.2, poll.2, prctl.2, ptrace.2, sched_setscheduler.2, select_tut.2, semget.2, sigaltstack.2, signalfd.2, sysctl.2, timer_settime.2, timerfd_create.2, wait.2, CPU_SET.3, argz_add.3, assert_perror.3, atexit.3, backtrace.3, bcmp.3, clearenv.3, ctime.3, dl_iterate_phdr.3, dlopen.3, ecvt.3, errno.3, error.3, ether_aton.3, exit.3, fenv.3, ferror.3, finite.3, flockfile.3, fnmatch.3, fpathconf.3, fpclassify.3, ftime.3, ftok.3, ftw.3, fwide.3, getaddrinfo.3, gethostbyname.3, getlogin.3, getnameinfo.3, getnetent.3, getopt.3, getprotoent.3, getrpcent.3, getservent.3, glob.3, hsearch.3, inet.3, isalpha.3, iswalnum.3, iswalpha.3, iswblank.3, iswcntrl.3, iswctype.3, iswdigit.3, iswgraph.3, iswlower.3, iswprint.3, iswpunct.3, iswspace.3, iswupper.3, iswxdigit.3, longjmp.3, lsearch.3, malloc.3, matherr.3, mblen.3, mbsinit.3, mbtowc.3, on_exit.3, printf.3, pthread_attr_init.3, pthread_attr_setaffinity_np.3, pthread_attr_setdetachstate.3, pthread_attr_setguardsize.3, pthread_attr_setinheritsched.3, pthread_attr_setschedparam.3, pthread_attr_setschedpolicy.3, pthread_attr_setscope.3, pthread_attr_setstack.3, pthread_attr_setstackaddr.3, pthread_attr_setstacksize.3, pthread_cancel.3, pthread_cleanup_push.3, pthread_equal.3, pthread_getattr_np.3, pthread_getcpuclockid.3, pthread_setaffinity_np.3, pthread_setcancelstate.3, pthread_setconcurrency.3, pthread_setschedparam.3, pthread_setschedprio.3, ptsname.3, putenv.3, putgrent.3, raise.3, rcmd.3, regex.3, rexec.3, rpc.3, rpmatch.3, rtnetlink.3, scandir.3, sem_init.3, setaliasent.3, setbuf.3, setenv.3, setjmp.3, signbit.3, stdio_ext.3, strtod.3, strtol.3, strtoul.3, system.3, termios.3, timeradd.3, tzset.3, ualarm.3, wctomb.3, xdr.3, st.4, tty_ioctl.4, core.5, elf.5, proc.5, bootparam.7, capabilities.7, icmp.7, ip.7, ipv6.7, math_error.7, mdoc.samples.7, mq_overview.7, pthreads.7, raw.7, regex.7, socket.7, tcp.7, tzselect.8: Global fix: s/non-zero/nonzero/
The tendency in English, as prescribed in style guides like
Chicago MoS, is towards removing hyphens after prefixes
like "non-" etc.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-01-16 16:40:55 +00:00
|
|
|
returns a nonzero value if
|
2004-11-03 13:51:07 +00:00
|
|
|
(fpclassify(x) == FP_NORMAL)
|
|
|
|
.TP
|
|
|
|
.BI isnan( x )
|
intro.1, time.1, adjtimex.2, capget.2, eventfd.2, fcntl.2, getrlimit.2, getsockopt.2, gettimeofday.2, intro.2, ioctl_list.2, ioperm.2, mlock.2, pivot_root.2, poll.2, prctl.2, ptrace.2, sched_setscheduler.2, select_tut.2, semget.2, sigaltstack.2, signalfd.2, sysctl.2, timer_settime.2, timerfd_create.2, wait.2, CPU_SET.3, argz_add.3, assert_perror.3, atexit.3, backtrace.3, bcmp.3, clearenv.3, ctime.3, dl_iterate_phdr.3, dlopen.3, ecvt.3, errno.3, error.3, ether_aton.3, exit.3, fenv.3, ferror.3, finite.3, flockfile.3, fnmatch.3, fpathconf.3, fpclassify.3, ftime.3, ftok.3, ftw.3, fwide.3, getaddrinfo.3, gethostbyname.3, getlogin.3, getnameinfo.3, getnetent.3, getopt.3, getprotoent.3, getrpcent.3, getservent.3, glob.3, hsearch.3, inet.3, isalpha.3, iswalnum.3, iswalpha.3, iswblank.3, iswcntrl.3, iswctype.3, iswdigit.3, iswgraph.3, iswlower.3, iswprint.3, iswpunct.3, iswspace.3, iswupper.3, iswxdigit.3, longjmp.3, lsearch.3, malloc.3, matherr.3, mblen.3, mbsinit.3, mbtowc.3, on_exit.3, printf.3, pthread_attr_init.3, pthread_attr_setaffinity_np.3, pthread_attr_setdetachstate.3, pthread_attr_setguardsize.3, pthread_attr_setinheritsched.3, pthread_attr_setschedparam.3, pthread_attr_setschedpolicy.3, pthread_attr_setscope.3, pthread_attr_setstack.3, pthread_attr_setstackaddr.3, pthread_attr_setstacksize.3, pthread_cancel.3, pthread_cleanup_push.3, pthread_equal.3, pthread_getattr_np.3, pthread_getcpuclockid.3, pthread_setaffinity_np.3, pthread_setcancelstate.3, pthread_setconcurrency.3, pthread_setschedparam.3, pthread_setschedprio.3, ptsname.3, putenv.3, putgrent.3, raise.3, rcmd.3, regex.3, rexec.3, rpc.3, rpmatch.3, rtnetlink.3, scandir.3, sem_init.3, setaliasent.3, setbuf.3, setenv.3, setjmp.3, signbit.3, stdio_ext.3, strtod.3, strtol.3, strtoul.3, system.3, termios.3, timeradd.3, tzset.3, ualarm.3, wctomb.3, xdr.3, st.4, tty_ioctl.4, core.5, elf.5, proc.5, bootparam.7, capabilities.7, icmp.7, ip.7, ipv6.7, math_error.7, mdoc.samples.7, mq_overview.7, pthreads.7, raw.7, regex.7, socket.7, tcp.7, tzselect.8: Global fix: s/non-zero/nonzero/
The tendency in English, as prescribed in style guides like
Chicago MoS, is towards removing hyphens after prefixes
like "non-" etc.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-01-16 16:40:55 +00:00
|
|
|
returns a nonzero value if
|
2004-11-03 13:51:07 +00:00
|
|
|
(fpclassify(x) == FP_NAN)
|
|
|
|
.TP
|
|
|
|
.BI isinf( x )
|
2005-06-24 12:38:56 +00:00
|
|
|
returns 1 if
|
|
|
|
.I x
|
|
|
|
is positive infinity, and \-1 if
|
|
|
|
.I x
|
|
|
|
is negative infinity.
|
2007-05-19 04:30:20 +00:00
|
|
|
.SH "CONFORMING TO"
|
2008-07-25 20:34:14 +00:00
|
|
|
C99, POSIX.1.
|
2008-08-07 06:57:15 +00:00
|
|
|
|
|
|
|
For
|
|
|
|
.BR isinf (),
|
intro.1, time.1, adjtimex.2, capget.2, eventfd.2, fcntl.2, getrlimit.2, getsockopt.2, gettimeofday.2, intro.2, ioctl_list.2, ioperm.2, mlock.2, pivot_root.2, poll.2, prctl.2, ptrace.2, sched_setscheduler.2, select_tut.2, semget.2, sigaltstack.2, signalfd.2, sysctl.2, timer_settime.2, timerfd_create.2, wait.2, CPU_SET.3, argz_add.3, assert_perror.3, atexit.3, backtrace.3, bcmp.3, clearenv.3, ctime.3, dl_iterate_phdr.3, dlopen.3, ecvt.3, errno.3, error.3, ether_aton.3, exit.3, fenv.3, ferror.3, finite.3, flockfile.3, fnmatch.3, fpathconf.3, fpclassify.3, ftime.3, ftok.3, ftw.3, fwide.3, getaddrinfo.3, gethostbyname.3, getlogin.3, getnameinfo.3, getnetent.3, getopt.3, getprotoent.3, getrpcent.3, getservent.3, glob.3, hsearch.3, inet.3, isalpha.3, iswalnum.3, iswalpha.3, iswblank.3, iswcntrl.3, iswctype.3, iswdigit.3, iswgraph.3, iswlower.3, iswprint.3, iswpunct.3, iswspace.3, iswupper.3, iswxdigit.3, longjmp.3, lsearch.3, malloc.3, matherr.3, mblen.3, mbsinit.3, mbtowc.3, on_exit.3, printf.3, pthread_attr_init.3, pthread_attr_setaffinity_np.3, pthread_attr_setdetachstate.3, pthread_attr_setguardsize.3, pthread_attr_setinheritsched.3, pthread_attr_setschedparam.3, pthread_attr_setschedpolicy.3, pthread_attr_setscope.3, pthread_attr_setstack.3, pthread_attr_setstackaddr.3, pthread_attr_setstacksize.3, pthread_cancel.3, pthread_cleanup_push.3, pthread_equal.3, pthread_getattr_np.3, pthread_getcpuclockid.3, pthread_setaffinity_np.3, pthread_setcancelstate.3, pthread_setconcurrency.3, pthread_setschedparam.3, pthread_setschedprio.3, ptsname.3, putenv.3, putgrent.3, raise.3, rcmd.3, regex.3, rexec.3, rpc.3, rpmatch.3, rtnetlink.3, scandir.3, sem_init.3, setaliasent.3, setbuf.3, setenv.3, setjmp.3, signbit.3, stdio_ext.3, strtod.3, strtol.3, strtoul.3, system.3, termios.3, timeradd.3, tzset.3, ualarm.3, wctomb.3, xdr.3, st.4, tty_ioctl.4, core.5, elf.5, proc.5, bootparam.7, capabilities.7, icmp.7, ip.7, ipv6.7, math_error.7, mdoc.samples.7, mq_overview.7, pthreads.7, raw.7, regex.7, socket.7, tcp.7, tzselect.8: Global fix: s/non-zero/nonzero/
The tendency in English, as prescribed in style guides like
Chicago MoS, is towards removing hyphens after prefixes
like "non-" etc.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-01-16 16:40:55 +00:00
|
|
|
the standards merely say that the return value is nonzero
|
2008-08-07 06:57:15 +00:00
|
|
|
if and only if the argument has an infinite value.
|
2007-05-16 02:54:18 +00:00
|
|
|
.SH NOTES
|
2005-06-24 12:38:56 +00:00
|
|
|
In glibc 2.01 and earlier,
|
2005-10-19 07:07:02 +00:00
|
|
|
.BR isinf ()
|
intro.1, time.1, adjtimex.2, capget.2, eventfd.2, fcntl.2, getrlimit.2, getsockopt.2, gettimeofday.2, intro.2, ioctl_list.2, ioperm.2, mlock.2, pivot_root.2, poll.2, prctl.2, ptrace.2, sched_setscheduler.2, select_tut.2, semget.2, sigaltstack.2, signalfd.2, sysctl.2, timer_settime.2, timerfd_create.2, wait.2, CPU_SET.3, argz_add.3, assert_perror.3, atexit.3, backtrace.3, bcmp.3, clearenv.3, ctime.3, dl_iterate_phdr.3, dlopen.3, ecvt.3, errno.3, error.3, ether_aton.3, exit.3, fenv.3, ferror.3, finite.3, flockfile.3, fnmatch.3, fpathconf.3, fpclassify.3, ftime.3, ftok.3, ftw.3, fwide.3, getaddrinfo.3, gethostbyname.3, getlogin.3, getnameinfo.3, getnetent.3, getopt.3, getprotoent.3, getrpcent.3, getservent.3, glob.3, hsearch.3, inet.3, isalpha.3, iswalnum.3, iswalpha.3, iswblank.3, iswcntrl.3, iswctype.3, iswdigit.3, iswgraph.3, iswlower.3, iswprint.3, iswpunct.3, iswspace.3, iswupper.3, iswxdigit.3, longjmp.3, lsearch.3, malloc.3, matherr.3, mblen.3, mbsinit.3, mbtowc.3, on_exit.3, printf.3, pthread_attr_init.3, pthread_attr_setaffinity_np.3, pthread_attr_setdetachstate.3, pthread_attr_setguardsize.3, pthread_attr_setinheritsched.3, pthread_attr_setschedparam.3, pthread_attr_setschedpolicy.3, pthread_attr_setscope.3, pthread_attr_setstack.3, pthread_attr_setstackaddr.3, pthread_attr_setstacksize.3, pthread_cancel.3, pthread_cleanup_push.3, pthread_equal.3, pthread_getattr_np.3, pthread_getcpuclockid.3, pthread_setaffinity_np.3, pthread_setcancelstate.3, pthread_setconcurrency.3, pthread_setschedparam.3, pthread_setschedprio.3, ptsname.3, putenv.3, putgrent.3, raise.3, rcmd.3, regex.3, rexec.3, rpc.3, rpmatch.3, rtnetlink.3, scandir.3, sem_init.3, setaliasent.3, setbuf.3, setenv.3, setjmp.3, signbit.3, stdio_ext.3, strtod.3, strtol.3, strtoul.3, system.3, termios.3, timeradd.3, tzset.3, ualarm.3, wctomb.3, xdr.3, st.4, tty_ioctl.4, core.5, elf.5, proc.5, bootparam.7, capabilities.7, icmp.7, ip.7, ipv6.7, math_error.7, mdoc.samples.7, mq_overview.7, pthreads.7, raw.7, regex.7, socket.7, tcp.7, tzselect.8: Global fix: s/non-zero/nonzero/
The tendency in English, as prescribed in style guides like
Chicago MoS, is towards removing hyphens after prefixes
like "non-" etc.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-01-16 16:40:55 +00:00
|
|
|
returns a nonzero value (actually: 1) if
|
2005-06-24 12:38:56 +00:00
|
|
|
.I x
|
2008-07-25 20:25:56 +00:00
|
|
|
is positive infinity or negative infinity.
|
2005-06-24 12:38:56 +00:00
|
|
|
(This is all that C99 requires.)
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH "SEE ALSO"
|
|
|
|
.BR finite (3),
|
|
|
|
.BR INFINITY (3),
|
2008-07-28 04:36:11 +00:00
|
|
|
.BR isgreater (3),
|
|
|
|
.BR signbit (3)
|