mirror of https://github.com/mkerrisk/man-pages
41 lines
920 B
Groff
41 lines
920 B
Groff
.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
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.\" Distributed under GPL
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.\"
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.TH CATANH 3 2008-08-11 "" "Linux Programmer's Manual"
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.SH NAME
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catanh, catanhf, catanhl \- complex arc tangents hyperbolic
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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 complex catanh(double complex " z );
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.br
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.BI "float complex catanhf(float complex " z );
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.br
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.BI "long double complex catanhl(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 catanh ()
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function calculates the complex arc hyperbolic tangent of
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.IR z .
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If \fIy\ =\ catanh(z)\fP, then \fIz\ =\ ctanh(y)\fP.
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The imaginary part of
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.I y
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is chosen in the interval [\-pi/2,pi/2].
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.LP
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One has:
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.nf
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catanh(z) = 0.5 * clog((1 + z) / (1 \- 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 "CONFORMING TO"
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C99.
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.SH "SEE ALSO"
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.BR atanh (3),
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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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