[thirdparty/man-pages.git] / man3 / catan.3

.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
.\" and Copyright (C) 2011 Michael Kerrisk <mtk.manpages@gamil.com>
.\"
.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
.\" Distributed under GPL
.\" %%%LICENSE_END
.\"
.TH CATAN 3 2015-04-19 "" "Linux Programmer's Manual"
.SH NAME
catan, catanf, catanl \- complex arc tangents
.SH SYNOPSIS
.B #include <complex.h>
.sp
.BI "double complex catan(double complex " z );
.br
.BI "float complex catanf(float complex " z );
.br
.BI "long double complex catanl(long double complex " z );
.sp
Link with \fI\-lm\fP.
.SH DESCRIPTION
These functions calculate the complex arc tangent of
.IR z .
If \fIy\ =\ catan(z)\fP, then \fIz\ =\ ctan(y)\fP.
The real part of y is chosen in the interval [\-pi/2,pi/2].
.LP
One has:
.nf

    catan(z) = (clog(1 + i * z) \- clog(1 \- i * z)) / (2 * i)
.fi
.SH VERSIONS
These functions first appeared in glibc in version 2.1.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw27 lb lb
l l l.
Interface	Attribute	Value
T{
.BR catan (),
.BR catanf (),
.BR catanl ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
.SH EXAMPLE
.nf
/* Link with "\-lm" */

#include <complex.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>

int
main(int argc, char *argv[])
{
    double complex z, c, f;
    double complex i = I;

    if (argc != 3) {
        fprintf(stderr, "Usage: %s <real> <imag>\\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    z = atof(argv[1]) + atof(argv[2]) * I;

    c = catan(z);
    printf("catan() = %6.3f %6.3f*i\\n", creal(c), cimag(c));

    f = (clog(1 + i * z) \- clog(1 \- i * z)) / (2 * i);
    printf("formula = %6.3f %6.3f*i\\n", creal(f2), cimag(f2));

    exit(EXIT_SUCCESS);
}
.fi
.SH SEE ALSO
.BR ccos (3),
.BR clog (3),
.BR ctan (3),
.BR complex (7)
Commit	Line	Data
	1	.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
	2	.\" and Copyright (C) 2011 Michael Kerrisk <mtk.manpages@gamil.com>
	3	.\"
	4	.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
	5	.\" Distributed under GPL
	6	.\" %%%LICENSE_END
	7	.\"
	8	.TH CATAN 3 2015-04-19 "" "Linux Programmer's Manual"
	9	.SH NAME
	10	catan, catanf, catanl \- complex arc tangents
	11	.SH SYNOPSIS
	12	.B #include <complex.h>
	13	.sp
	14	.BI "double complex catan(double complex " z );
	15	.br
	16	.BI "float complex catanf(float complex " z );
	17	.br
	18	.BI "long double complex catanl(long double complex " z );
	19	.sp
	20	Link with \fI\-lm\fP.
	21	.SH DESCRIPTION
	22	These functions calculate the complex arc tangent of
	23	.IR z .
	24	If \fIy\ =\ catan(z)\fP, then \fIz\ =\ ctan(y)\fP.
	25	The real part of y is chosen in the interval [\-pi/2,pi/2].
	26	.LP
	27	One has:
	28	.nf
	29
	30	catan(z) = (clog(1 + i * z) \- clog(1 \- i * z)) / (2 * i)
	31	.fi
	32	.SH VERSIONS
	33	These functions first appeared in glibc in version 2.1.
	34	.SH ATTRIBUTES
	35	For an explanation of the terms used in this section, see
	36	.BR attributes (7).
	37	.TS
	38	allbox;
	39	lbw27 lb lb
	40	l l l.
	41	Interface Attribute Value
	42	T{
	43	.BR catan (),
	44	.BR catanf (),
	45	.BR catanl ()
	46	T} Thread safety MT-Safe
	47	.TE
	48	.SH CONFORMING TO
	49	C99, POSIX.1-2001, POSIX.1-2008.
	50	.SH EXAMPLE
	51	.nf
	52	/* Link with "\-lm" */
	53
	54	#include <complex.h>
	55	#include <stdlib.h>
	56	#include <unistd.h>
	57	#include <stdio.h>
	58
	59	int
	60	main(int argc, char *argv[])
	61	{
	62	double complex z, c, f;
	63	double complex i = I;
	64
	65	if (argc != 3) {
	66	fprintf(stderr, "Usage: %s <real> <imag>\\n", argv[0]);
	67	exit(EXIT_FAILURE);
	68	}
	69
	70	z = atof(argv[1]) + atof(argv[2]) * I;
	71
	72	c = catan(z);
	73	printf("catan() = %6.3f %6.3f*i\\n", creal(c), cimag(c));
	74
	75	f = (clog(1 + i * z) \- clog(1 \- i * z)) / (2 * i);
	76	printf("formula = %6.3f %6.3f*i\\n", creal(f2), cimag(f2));
	77
	78	exit(EXIT_SUCCESS);
	79	}
	80	.fi
	81	.SH SEE ALSO
	82	.BR ccos (3),
	83	.BR clog (3),
	84	.BR ctan (3),
	85	.BR complex (7)