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modf(3p) — Linux manual page

MODF(3P)                POSIX Programmer's ManualMODF(3P)

PROLOG        top

       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.

NAME        top

       modf, modff, modfl — decompose a floating-point number

SYNOPSIS        top

       #include <math.h>       double modf(doublex, double *iptr);       float modff(floatvalue, float *iptr);       long double modfl(long doublevalue, long double *iptr);

DESCRIPTION        top

       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.1‐2017 defers to the ISO C standard.       These functions shall break the argumentx into integral and       fractional parts, each of which has the same sign as the argument.       It stores the integral part as adouble(for themodf() function),       afloat(for themodff() function), or along double(for themodfl() function), in the object pointed to byiptr.

RETURN VALUE        top

       Upon successful completion, these functions shall return the       signed fractional part ofx.       Ifx is NaN, a NaN shall be returned, and *iptr shall be set to a       NaN.       Ifx is ±Inf, ±0 shall be returned, and *iptr shall be set to       ±Inf.

ERRORS        top

       No errors are defined.The following sections are informative.

EXAMPLES        top

       None.

APPLICATION USAGE        top

       Themodf() function computes the function result and *iptr such       that:           a = modf(x, iptr) ;           x == a+*iptr ;       allowing for the usual floating-point inaccuracies.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

frexp(3p),isnan(3p),ldexp(3p)       The Base Definitions volume of POSIX.1‐2017,math.h(0p)

COPYRIGHT        top

       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 athttp://www.opengroup.org/unix/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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017MODF(3P)

Pages that refer to this page:math.h(0p), tgmath.h(0p), frexp(3p)

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