1994-05-27 05:00:24 +00:00
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.\" Copyright (c) 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)isinf.3 8.2 (Berkeley) 1/29/94
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1999-08-28 00:22:10 +00:00
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.\" $FreeBSD$
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1994-05-27 05:00:24 +00:00
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.\"
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.Dd January 29, 1994
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.Dt ISINF 3
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.Os
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.Sh NAME
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.Nm isinf ,
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.Nm isnan
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.Nd test for infinity or not-a-number
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.Sh SYNOPSIS
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.Ft int
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.Fn isinf double
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.Ft int
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.Fn isnan double
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.Sh DESCRIPTION
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The
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1999-06-07 02:42:31 +00:00
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.Fn isinf
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1994-05-27 05:00:24 +00:00
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function
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returns 1 if the number is
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.Dq \\*(If ,
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otherwise 0.
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.Pp
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The
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.Fn isnan
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function
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returns 1 if the number is
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.Dq not-a-number ,
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otherwise 0.
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.Sh SEE ALSO
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.Xr math 3
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.Rs
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.%T "IEEE Standard for Binary Floating-Point Arithmetic"
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.%Q ANSI
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.%R Std 754-1985
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.Re
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.Sh BUGS
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Neither the
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.Tn VAX
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nor the Tahoe floating point have distinguished values
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for either infinity or not-a-number.
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These routines always return 0 on those architectures.
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