mathalib.html

Vxworks API操作系统和驱动程序设计API。压缩的HTML文件

</blockquote><h1>irintf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>irintf(&nbsp;)</strong> - convert a single-precision value to an integer</p>

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

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

This routine converts a single-precision value <i>x</i> to an integer using the 
selected IEEE rounding direction.
<p>
</blockquote><h4>CAVEAT</h4><blockquote><p>
<p>
The rounding direction is not pre-selectable
and is fixed as round-to-the-nearest.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The integer representation of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>iroundf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>iroundf(&nbsp;)</strong> - round a number to the nearest integer</p>

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

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

This routine rounds a single-precision value <i>x</i> to the nearest 
integer value.
<p>
</blockquote><h4>NOTE</h4><blockquote><p>
<p>
If <i>x</i> is spaced evenly between two integers, the even integer is
returned.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The integer nearest to <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

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

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

This routine returns the logarithm 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 natural logarithm of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

<hr>
<a name="log10f"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>log10f(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>log10f(&nbsp;)</strong> - compute a base-10 logarithm (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float log10f
    (
    float x    /* value to compute the base-10 logarithm of */
    )
</pre>

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

This routine returns the base-10 logarithm 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 base-10 logarithm of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

<hr>
<a name="log2f"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>log2f(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>log2f(&nbsp;)</strong> - compute a base-2 logarithm</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float log2f
    (
    float x    /* value to compute the base-2 logarithm of */
    )
</pre>

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

This routine returns the base-2 logarithm 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 base-2 logarithm of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>powf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>powf(&nbsp;)</strong> - compute the value of a number raised to a specified power (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float powf
    (
    float x,   /* operand  */
    float y    /* exponent */
    )
</pre>

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

This routine returns the value of <i>x</i> to the power of <i>y</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 value of <i>x</i> to the power of <i>y</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>roundf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>roundf(&nbsp;)</strong> - round a number to the nearest integer</p>

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

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

This routine rounds a single-precision value <i>x</i> to the nearest 
integral value.
<p>
</blockquote><h4>INCLUDE FILES</h4><blockquote><p>
<b>math.h</b> 
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The single-precision representation of <i>x</i> rounded to the
nearest integral value.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

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

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

This routine returns the sine 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>
<p>
The single-precision sine of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>sincosf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>sincosf(&nbsp;)</strong> - compute both a sine and cosine</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void sincosf
    (
    float x,          /* angle in radians */
    float *sinResult, /* sine result buffer */
    float *cosResult  /* cosine result buffer */
    )
</pre>

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

This routine computes both the sine and cosine of <i>x</i> in single precision.
The sine is copied to <i>sinResult</i> and the cosine is copied to <i>cosResult</i>.
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>
N/A
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float sinhf
    (
    float x   /* number whose hyperbolic sine is required */
    )
</pre>

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

This routine returns the hyperbolic sine 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 hyperbolic sine of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

</blockquote><h1>sqrtf(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>sqrtf(&nbsp;)</strong> - compute a non-negative square root (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float sqrtf
    (
    float x    /* value to compute the square root of */
    )
</pre>

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

This routine returns the non-negative square 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 square 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="tanf"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

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

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

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

This routine returns the tangent 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 tangent of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float tanhf
    (
    float x    /* number whose hyperbolic tangent is required */
    )
</pre>

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

This routine returns the hyperbolic tangent 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 hyperbolic tangent of <i>x</i>.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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

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

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>float truncf
    (
    float x   /* value to truncate */
    )
</pre>

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

This routine discards the fractional part of a single-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 single precision.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./mathALib.html#top">mathALib</a></b>

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