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From: "cournape at gmail dot com" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug libc/10355] New: cabs(z) == nan if z = inf + j * nan Date: Wed, 01 Jul 2009 09:55:00 -0000 [thread overview] Message-ID: <20090701095524.10355.cournape@gmail.com> (raw) Hi, I came across the following when using cabs and the glibc: #define _ISOC99_SOURCE #include <complex.h> #include <stdio.h> #include <math.h> int main(void) { complex z; double x, y; x = INFINITY; y = NAN; z = x + I * y; printf("%f\n", cabs(z)); printf("%f\n", hypot(x, y)); return 0; } This prints: nan inf I believe that cabs behavior is incorrect in this case if I read the C99 standard correctly (Section G 6.6 from the committee draft of september 2007): " Each of the functions cabs and carg is specified by a formula in terms of a real function (whose special cases are covered in annex F): cabs(x + iy) = hypot(x, y) carg(x + iy) = atan2(y, x) " glibc version: 2.8 gcc version: 4.3.2 -- Summary: cabs(z) == nan if z = inf + j * nan Product: glibc Version: unspecified Status: NEW Severity: normal Priority: P2 Component: libc AssignedTo: drepper at redhat dot com ReportedBy: cournape at gmail dot com CC: glibc-bugs at sources dot redhat dot com http://sourceware.org/bugzilla/show_bug.cgi?id=10355 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.
next reply other threads:[~2009-07-01 9:55 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2009-07-01 9:55 cournape at gmail dot com [this message] 2009-10-30 6:29 ` [Bug libc/10355] " drepper at redhat dot com
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