mathalib.html

Vxworks API操作系统和驱动程序设计API。压缩的HTML文件

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

</blockquote><h1>trunc(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>trunc(&nbsp;)</strong> - truncate to integer</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>double trunc
    (
    double x  /* value to truncate */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine discards the fractional part of a double-precision value <i>x</i>.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The integer portion of <i>x</i>, represented in double-precision.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>acosf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>acosf(&nbsp;)</strong> - compute an arc cosine (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float acosf
    (
    float x   /* number between -1 and 1 */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine computes the arc cosine of <i>x</i> in single precision.
If <i>x</i> is the cosine of an angle <i>T</i>, this function returns <i>T</i>.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision arc cosine of <i>x</i> in the range 0
to pi radians.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>asinf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>asinf(&nbsp;)</strong> - compute an arc sine (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float asinf
    (
    float x   /* number between -1 and 1 */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine computes the arc sine of <i>x</i> in single precision.
If <i>x</i> is the sine of an angle <i>T</i>, this function returns <i>T</i>.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision arc sine of <i>x</i> in the range
-pi/2 to pi/2 radians.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>atanf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>atanf(&nbsp;)</strong> - compute an arc tangent (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float atanf
    (
    float x   /* tangent of an angle */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine computes the arc tangent of <i>x</i> in single precision.
If <i>x</i> is the tangent of an angle <i>T</i>, this function returns <i>T</i> 
(in radians).
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision arc tangent of <i>x</i> in the range -pi/2 to pi/2.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

<hr>
<a name="atan2f"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>atan2f(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>atan2f(&nbsp;)</strong> - compute the arc tangent of y/x (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float atan2f
    (
    float y,          /* numerator */
    float x           /* denominator */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the principal value of the arc tangent of <i>y</i>/<i>x</i>
in single precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The single-precision arc tangent of <i>y</i>/<i>x</i> in the range -pi to pi.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>cbrtf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>cbrtf(&nbsp;)</strong> - compute a cube root</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float cbrtf
    (
    float x  /* argument */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the cube root of <i>x</i> in single precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision cube root of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float ceilf
    (
    float v   /* value to find the ceiling of */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

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

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

</blockquote><h1>cosf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>cosf(&nbsp;)</strong> - compute a cosine (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float cosf
    (
    float x   /* angle in radians */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the cosine of <i>x</i> in single precision.
The angle <i>x</i> is expressed in radians.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision cosine of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>coshf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>coshf(&nbsp;)</strong> - compute a hyperbolic cosine (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float coshf
    (
    float x   /* value to compute the hyperbolic cosine of */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the hyperbolic cosine of <i>x</i> in single precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The single-precision hyperbolic cosine of <i>x</i> if the parameter is greater
than 1.0, or NaN if the parameter is less than 1.0.
<p>
Special cases:<br>
&nbsp;If&nbsp;<i>x</i>&nbsp;is&nbsp;+INF,&nbsp;-INF,&nbsp;or&nbsp;NaN,&nbsp;<b><a href="./mathALib.html#coshf">coshf</a>(&nbsp;)</b>&nbsp;returns&nbsp;<i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float expf
    (
    float x   /* exponent */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the exponential of <i>x</i> in single precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The single-precision exponential value of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

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

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

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

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

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

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

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the largest integer less than or equal to <i>v</i>,
in single 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 single precision.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

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

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns the remainder of <i>x</i>/<i>y</i> with the sign of <i>x</i>,
in single precision.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
The single-precision modulus of <i>x</i>/<i>y</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>infinityf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>infinityf(&nbsp;)</strong> - return a very large float</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float infinityf (void)
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
<p>

This routine returns a very large float.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision representation of positive infinity.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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