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diff --git a/man-pages-posix-2017/man3p/tgamma.3p b/man-pages-posix-2017/man3p/tgamma.3p new file mode 100644 index 0000000..19880a5 --- /dev/null +++ b/man-pages-posix-2017/man3p/tgamma.3p @@ -0,0 +1,251 @@ +'\" et +.TH TGAMMA "3P" 2017 "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. +.\" +.EQ +delim $$ +.EN +.SH NAME +tgamma, +tgammaf, +tgammal +\(em compute gamma(\|) function +.SH SYNOPSIS +.LP +.nf +#include <math.h> +.P +double tgamma(double \fIx\fP); +float tgammaf(float \fIx\fP); +long double tgammal(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\(hy2017 defers to the ISO\ C standard. +.P +These functions shall compute $\(*G ( ^ x )$ +where $\(*G ( ^ x )$ is defined as +$int from 0 to inf e"^" " "{ - t } t"^" " "{ x - 1 } dt$. +.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 gamma of +.IR x . +.P +If +.IR x +is a negative integer, a +domain +error may occur and either a NaN (if supported) or an +implementation-defined value shall be returned. +On systems that support the IEC 60559 Floating-Point option, a domain +error shall occur and a NaN shall be returned. +.P +If +.IR x +is \(+-0, +\fItgamma\fR(), +\fItgammaf\fR(), +and +\fItgammal\fR() +shall return \(+-HUGE_VAL, \(+-HUGE_VALF, and \(+-HUGE_VALL, +respectively. +On systems that support the IEC 60559 Floating-Point option, a pole +error shall occur; +otherwise, a +pole +error may occur. +.P +If the correct value would cause overflow, a range error shall occur +and +\fItgamma\fR(), +\fItgammaf\fR(), +and +\fItgammal\fR() +shall return \(+-HUGE_VAL, \(+-HUGE_VALF, or \(+-HUGE_VALL, +respectively, with the same sign as the correct value of the function. +.P +If the correct value would cause underflow, +and is not representable, +a range error may occur, and +\fItgamma\fR(), +\fItgammaf\fR(), +and +\fItgammal\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 the correct value would cause underflow, and is representable, +a range error may occur and the correct value shall be returned. +.P +If +.IR x +is subnormal and 1/\c +.IR x +is representable, 1/\c +.IR x +should be returned. +.P +If +.IR x +is NaN, a NaN shall be returned. +.P +If +.IR x +is +Inf, +.IR x +shall be returned. +.P +If +.IR x +is \-Inf, a domain error shall occur, and a NaN shall be returned. +.SH ERRORS +These functions shall fail if: +.IP "Domain\ Error" 12 +The value of +.IR x +is a negative integer, or +.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 "Pole\ Error" 12 +The value of +.IR x +is zero. +.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 divide-by-zero floating-point exception shall be +raised. +.br +.RE +.IP "Range\ Error" 12 +The value 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 +.P +These functions may fail if: +.IP "Domain\ Error" 12 +The value of +.IR x +is a negative integer. +.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 "Pole\ Error" 12 +The value of +.IR x +is zero. +.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 divide-by-zero floating-point exception shall be +raised. +.RE +.IP "Range\ Error" 12 +The result underflows. +.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 +None. +.SH "APPLICATION USAGE" +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 +This function is named +\fItgamma\fR() +in order to avoid conflicts with the historical +.IR gamma (\|) +and +\fIlgamma\fR() +functions. +.SH "FUTURE DIRECTIONS" +It is possible that the error response for a negative integer argument +may be changed to a pole error and a return value of \(+-Inf. +.SH "SEE ALSO" +.IR "\fIfeclearexcept\fR\^(\|)", +.IR "\fIfetestexcept\fR\^(\|)", +.IR "\fIlgamma\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2017, +.IR "Section 4.20" ", " "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 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +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.opengroup.org/unix/online.html . +.PP +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 . |