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diff --git a/man3/frexp.3 b/man3/frexp.3 new file mode 100644 index 000000000..36764dfbd --- /dev/null +++ b/man3/frexp.3 @@ -0,0 +1,81 @@ +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) +.\" Modified 2002-07-27 by Walter Harms +.\" (walter.harms@informatik.uni-oldenburg.de) +.\" +.TH FREXP 3 2002-07-27 "" "Linux Programmer's Manual" +.SH NAME +frexp, frexpf, frexpl \- convert floating-point number to fractional +and integral components +.SH SYNOPSIS +.nf +.B #include <math.h> +.sp +.BI "double frexp(double " x ", int *" exp ); +.sp +.BI "float frexpf(float " x ", int *" exp ); +.sp +.BI "long double frexpl(long double " x ", int *" exp ); +.fi +.sp +Link with \-lm. +.SH DESCRIPTION +The \fBfrexp()\fP function is used to split the number \fIx\fP into a +normalized fraction and an exponent which is stored in \fIexp\fP. +.SH "RETURN VALUE" +The \fBfrexp()\fP function returns the normalized fraction. If the +argument \fIx\fP is not zero, the normalized fraction is \fIx\fP +times a power of two, and is always in the range 1/2 (inclusive) to +1 (exclusive). If \fIx\fP is zero, then the normalized fraction is +zero and zero is stored in \fIexp\fP. +.SH "CONFORMING TO" +SVID 3, POSIX, BSD 4.3, ISO 9899. +The float and the long double variants are C99 requirements. +.SH EXAMPLE +.nf +#include <stdio.h> +#include <math.h> +#include <float.h> +int main () { + double d = 2560; + int e; + double f = frexp(d, &e); + printf("frexp(%g, &e) = %g: %g * %d^%d = %g\en", + d, f, f, FLT_RADIX, e, d); + return 0; +} +.fi +.sp +This program prints +.sp +.in +5 +frexp(2560, &e) = 0.625: 0.625 * 2^12 = 2560 +.in +.SH "SEE ALSO" +.BR ldexp (3), +.BR modf (3) |