ansimath.html

Vxworks API操作系统和驱动程序设计API。压缩的HTML文件

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the hyperbolic cosine of <i>x</i> in
double precision (IEEE double, 53 bits).
<p>
A range error occurs if <i>x</i> is too large.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The double-precision hyperbolic cosine of <i>x</i>.
<p>
Special cases:<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;+INF,&nbsp;-INF,&nbsp;or&nbsp;NaN,&nbsp;<b><a href="./mathALib.html#cosh">cosh</a>(&nbsp;)</b>&nbsp;returns&nbsp;<i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>
<p>


<hr>
<a name="exp"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>exp(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>exp(&nbsp;)</strong> - compute an exponential value (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double exp
    (
    double x                  /* exponent */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the exponential value of <i>x</i> in
double precision (IEEE double, 53 bits).
<p>
A range error occurs if <i>x</i> is too large.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The double-precision exponential value of <i>x</i>.
<p>
Special cases:<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;+INF&nbsp;or&nbsp;NaN,&nbsp;<b><a href="./mathALib.html#exp">exp</a>(&nbsp;)</b>&nbsp;returns&nbsp;<i>x</i>.<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;-INF,&nbsp;it&nbsp;returns&nbsp;0.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>
<p>


<hr>
<a name="fabs"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>fabs(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>fabs(&nbsp;)</strong> - compute an absolute value (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double fabs
    (
    double v                  /* number to return the absolute value of */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the absolute value of <i>v</i> in double precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The double-precision absolute value of <i>v</i>.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
EDOM, ERANGE
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>

<hr>
<a name="floor"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>floor(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>floor(&nbsp;)</strong> - compute the largest integer less than or equal to a specified value (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double floor
    (
    double v                  /* value to find the floor of */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the largest integer less than or equal to <i>v</i>, in
double precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The largest integral value less than or equal to <i>v</i>, in double precision.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>

<hr>
<a name="fmod"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>fmod(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>fmod(&nbsp;)</strong> - compute the remainder of x/y (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double fmod
    (
    double x,                 /* numerator */
    double y                  /* denominator */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the remainder of <i>x</i>/<i>y</i> with the sign of <i>x</i>,
in double precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The value <i>x</i> - <i>i</i> * <i>y</i>, for some integer <i>i</i>.  If <i>y</i> is
non-zero, the result has the same sign as <i>x</i> and magnitude less than the
magnitude of <i>y</i>.  If <i>y</i> is zero, <b><a href="./mathALib.html#fmod">fmod</a>(&nbsp;)</b> returns zero.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
EDOM
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>

<hr>
<a name="frexp"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>frexp(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>frexp(&nbsp;)</strong> - break a floating-point number into a normalized fraction and power of 2 (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double frexp
    (
    double value,             /* number to be normalized */
    int *  pexp               /* pointer to the exponent */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine breaks a double-precision number <i>value</i> into a normalized
fraction and integral power of 2.  It stores the integer exponent in <i>pexp</i>.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The double-precision value <i>x</i>, such that the magnitude of <i>x</i> is
in the interval [1/2,1) or zero, and <i>value</i> equals <i>x</i> times
2 to the power of <i>pexp</i>. If <i>value</i> is zero, both parts of the result
are zero.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
EDOM
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>

<hr>
<a name="ldexp"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>ldexp(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>ldexp(&nbsp;)</strong> - multiply a number by an integral power of 2 (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double ldexp
    (
    double v,                 /* a floating point number */
    int    xexp               /* exponent */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine multiplies a floating-point number by an integral power of 2.
A range error may occur.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The double-precision value of <i>v</i> times 2 to the power of <i>xexp</i>.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>

<hr>
<a name="log"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>log(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>log(&nbsp;)</strong> - compute a natural logarithm (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double log
    (
    double x                  /* value to compute the natural logarithm of */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the natural logarithm of <i>x</i>
in double precision (IEEE double, 53 bits).
<p>
A domain error occurs if the argument is negative.  A range error may occur
if the argument is zero.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The double-precision natural logarithm of <i>x</i>.
<p>
Special cases:<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;<&nbsp;0&nbsp;(including&nbsp;-INF),&nbsp;it&nbsp;returns&nbsp;NaN&nbsp;with&nbsp;signal.<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;+INF,&nbsp;it&nbsp;returns&nbsp;<i>x</i>&nbsp;with&nbsp;no&nbsp;signal.<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;0,&nbsp;it&nbsp;returns&nbsp;-INF&nbsp;with&nbsp;signal.<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;NaN&nbsp;it&nbsp;returns&nbsp;<i>x</i>&nbsp;with&nbsp;no&nbsp;signal.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>
<p>


<hr>
<a name="log10"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>log10(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>log10(&nbsp;)</strong> - compute a base-10 logarithm (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double log10
    (
    double x                  /* value to compute the base-10 logarithm of */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns the base 10 logarithm of <i>x</i> in
double precision (IEEE double, 53 bits).
<p>
A domain error occurs if the argument is negative.  A range error may
if the argument is zero.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b>
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The double-precision base-10 logarithm of <i>x</i>.
<p>
Special cases:<br>
&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;<i>x</i>&nbsp;<&nbsp;0,&nbsp;<b><a href="./mathALib.html#log10">log10</a>(&nbsp;)</b>&nbsp;returns&nbsp;NaN&nbsp;with&nbsp;signal.<br>
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;<i>x</i>&nbsp;is&nbsp;+INF,&nbsp;it&nbsp;returns&nbsp;<i>x</i>&nbsp;with&nbsp;no&nbsp;signal.<br>
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;<i>x</i>&nbsp;is&nbsp;0,&nbsp;it&nbsp;returns&nbsp;-INF&nbsp;with&nbsp;signal.<br>
&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;<i>x</i>&nbsp;is&nbsp;NaN&nbsp;it&nbsp;returns&nbsp;<i>x</i>&nbsp;with&nbsp;no&nbsp;signal.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./ansiMath.html#top">ansiMath</a></b>, <b><a href="./mathALib.html#top">mathALib</a></b>
<p>


<hr>
<a name="modf"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>modf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>modf(&nbsp;)</strong> - separate a floating-point number into integer and fraction parts (ANSI)</p>