diff options
Diffstat (limited to 'man-pages-posix-2013/man3p/tan.3p')
| -rw-r--r-- | man-pages-posix-2013/man3p/tan.3p | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/man-pages-posix-2013/man3p/tan.3p b/man-pages-posix-2013/man3p/tan.3p new file mode 100644 index 0000000..29c43ae --- /dev/null +++ b/man-pages-posix-2013/man3p/tan.3p @@ -0,0 +1,206 @@ +'\" et +.TH TAN "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. + +.SH NAME +tan, +tanf, +tanl +\(em tangent function +.SH SYNOPSIS +.LP +.nf +#include <math.h> +.P +double tan(double \fIx\fP); +float tanf(float \fIx\fP); +long double tanl(long double \fIx\fP); +.fi +.SH DESCRIPTION +The functionality described on this reference page is aligned with the +ISO\ C standard. Any conflict between the requirements described here and the +ISO\ C standard is unintentional. This volume of POSIX.1\(hy2008 defers to the ISO\ C standard. +.P +These functions shall compute the tangent of their argument +.IR x , +measured in radians. +.P +An application wishing to check for error situations should set +.IR errno +to zero and call +.IR feclearexcept (FE_ALL_EXCEPT) +before calling these functions. On return, if +.IR errno +is non-zero or \fIfetestexcept\fR(FE_INVALID | FE_DIVBYZERO | +FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred. +.SH "RETURN VALUE" +Upon successful completion, these functions shall return the tangent of +.IR x . +.P +If the correct value would cause underflow, +and is not representable, +a range error may occur, and +\fItan\fR(), +\fItanf\fR(), +and +\fItanl\fR() +shall return +0.0, or +(if IEC 60559 Floating-Point is not supported) an implementation-defined +value no greater in magnitude than DBL_MIN, FLT_MIN, and LDBL_MIN, +respectively. +.P +If +.IR x +is NaN, a NaN shall be returned. +.P +If +.IR x +is \(+-0, +.IR x +shall be returned. +.P +If +.IR x +is subnormal, a range error may occur +.br +and +.IR x +should be returned. +.P +If +.IR x +is not returned, +\fItan\fR(), +\fItanf\fR(), +and +\fItanl\fR() +shall return an implementation-defined value no greater in magnitude +than DBL_MIN, FLT_MIN, and LDBL_MIN, respectively. +.P +If +.IR x +is \(+-Inf, a domain error shall occur, and either a NaN (if +supported), or an implementation-defined value shall be returned. +.P +If the correct value would cause underflow, and is representable, +a range error may occur and the correct value shall be returned. +.P +If the correct value would cause overflow, a range error shall occur +and +\fItan\fR(), +\fItanf\fR(), +and +\fItanl\fR() +shall return \(+-HUGE_VAL, \(+-HUGE_VALF, and \(+-HUGE_VALL, +respectively, with the same sign as the correct value of the function. +.SH ERRORS +These functions shall fail if: +.IP "Domain\ Error" 12 +The value of +.IR x +is \(+-Inf. +.RS 12 +.P +If the integer expression (\fImath_errhandling\fR & MATH_ERRNO) is +non-zero, then +.IR errno +shall be set to +.BR [EDOM] . +If the integer expression (\fImath_errhandling\fR & MATH_ERREXCEPT) is +non-zero, then the invalid floating-point exception shall be raised. +.RE +.IP "Range\ Error" 12 +The result overflows +.RS 12 +.P +If the integer expression (\fImath_errhandling\fR & MATH_ERRNO) is +non-zero, then +.IR errno +shall be set to +.BR [ERANGE] . +If the integer expression (\fImath_errhandling\fR & MATH_ERREXCEPT) is +non-zero, then the overflow floating-point exception shall be raised. +.RE +.br +.P +These functions may fail if: +.IP "Range\ Error" 12 +The result underflows, +or the value of +.IR x +is subnormal. +.RS 12 +.P +If the integer expression (\fImath_errhandling\fR & MATH_ERRNO) is +non-zero, then +.IR errno +shall be set to +.BR [ERANGE] . +If the integer expression (\fImath_errhandling\fR & MATH_ERREXCEPT) is +non-zero, then the underflow floating-point exception shall be raised. +.RE +.LP +.IR "The following sections are informative." +.SH EXAMPLES +.SS "Taking the Tangent of a 45-Degree Angle" +.sp +.RS 4 +.nf +\fB +#include <math.h> +\&... +double radians = 45.0 * M_PI / 180; +double result; +\&... +result = tan (radians); +.fi \fR +.P +.RE +.SH "APPLICATION USAGE" +There are no known floating-point representations such that for a +normal argument, +.IR tan (\c +.IR x ) +is either overflow or underflow. +.P +These functions may lose accuracy when their argument is near a +multiple of \(*p/2 or is far from 0.0. +.P +On error, the expressions (\fImath_errhandling\fR & MATH_ERRNO) and +(\fImath_errhandling\fR & MATH_ERREXCEPT) are independent of each +other, but at least one of them must be non-zero. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "\fIatan\fR\^(\|)", +.IR "\fIfeclearexcept\fR\^(\|)", +.IR "\fIfetestexcept\fR\^(\|)", +.IR "\fIisnan\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "Section 4.19" ", " "Treatment of Error Conditions for Mathematical Functions", +.IR "\fB<math.h>\fP" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, Copyright (C) 2013 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.unix.org/online.html . + +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |