122 lines
3.0 KiB
Groff
122 lines
3.0 KiB
Groff
.\" Copyright (c) 2004 Stefan Farfeleder
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.\" 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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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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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.\" $FreeBSD$
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.\"
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.Dd August 7, 2008
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.Dt CIMAG 3
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.Os
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.Sh NAME
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.Nm cimag , cimagf , cimagl ,
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.Nm conj , conjf , conjl ,
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.Nm cproj , cprojf , cprojl ,
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.Nm creal , crealf , creall
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.Nd "functions to manipulate complex numbers"
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.Sh LIBRARY
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.Lb libm
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.Sh SYNOPSIS
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.In complex.h
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.Ft double
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.Fn cimag "double complex z"
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.Ft float
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.Fn cimagf "float complex z"
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.Ft "long double"
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.Fn cimagl "long double complex z"
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.Ft "double complex"
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.Fn conj "double complex z"
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.Ft "float complex"
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.Fn conjf "float complex z"
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.Ft "long double complex"
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.Fn conjl "long double complex z"
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.Ft "double complex"
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.Fn cproj "double complex z"
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.Ft "float complex"
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.Fn cprojf "float complex z"
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.Ft "long double complex"
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.Fn cprojl "long double complex z"
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.Ft double
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.Fn creal "double complex z"
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.Ft float
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.Fn crealf "float complex z"
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.Ft "long double"
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.Fn creall "long double complex z"
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.Sh DESCRIPTION
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Let
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.Sm off
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.Fa a + b * Em i
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.Sm on
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denote the complex number
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.Fa z .
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.Pp
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The
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.Fn creal
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functions return the real part
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.Fa a ,
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and the
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.Fn cimag
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functions return the imaginary part
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.Fa b .
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.Pp
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The
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.Fn conj
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functions return the complex conjugate
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.Sm off
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.Fa a - b * Em i .
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.Sm on
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.Pp
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The
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.Fn cproj
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functions return the projection onto the Riemann sphere.
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If
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.Fa z
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contains an infinite component, then the result is
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.Fa \*(If \*(Pm 0 Ns * Ns Em i ,
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where the (zero) imaginary part of the result has the same sign as
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.Fa b .
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Otherwise, the result is
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.Fa z .
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.Pp
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These functions do not signal any floating point exceptions.
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.Sh STANDARDS
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The
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.Fn cimag ,
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.Fn conj ,
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.Fn cproj ,
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and
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.Fn creal
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functions conform to
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.St -isoC-99 .
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.Sh HISTORY
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The
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.Fn cimag ,
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.Fn conj
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and
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.Fn creal
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functions first appeared in
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.Fx 5.3 .
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The
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.Fn cproj
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functions appeared in
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.Fx 8.0.
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