mirror of https://github.com/mkerrisk/man-pages
50 lines
994 B
Groff
50 lines
994 B
Groff
.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
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.\"
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.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
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.\" Distributed under GPL
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.\" %%%LICENSE_END
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.\"
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.TH CREAL 3 2013-09-18 "" "Linux Programmer's Manual"
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.SH NAME
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creal, crealf, creall \- get real part of a complex number
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.SH SYNOPSIS
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.B #include <complex.h>
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.sp
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.BI "double creal(double complex " z );
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.br
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.BI "float crealf(float complex " z );
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.br
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.BI "long double creall(long double complex " z );
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.sp
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Link with \fI\-lm\fP.
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.SH DESCRIPTION
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The
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.BR creal ()
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function returns the real part of the complex number
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.IR z .
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.LP
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One has:
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.nf
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z = creal(z) + I * cimag(z)
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.fi
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.SH VERSIONS
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These functions first appeared in glibc in version 2.1.
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.SH ATTRIBUTES
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.SS Multithreading (see pthreads(7))
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The
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.BR creal (),
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.BR crealf (),
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and
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.BR creall ()
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functions are thread-safe.
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.SH CONFORMING TO
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C99.
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.SH NOTES
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The gcc supports also __real__.
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That is a GNU extension.
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.SH SEE ALSO
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.BR cabs (3),
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.BR cimag (3),
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.BR complex (7)
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