<ppdoc>
<copyright>
    Copyright (c) 2001 by Addison Wesley Longman.  This
    material may be distributed only subject to the terms and
    conditions set forth in the Open Publication License, v1.0 or
    later (the latest version is presently available at
    http://www.opencontent.org/openpub/).
</copyright>
<class name="Float" super="Numeric" type="class" ref="xref-000001">  
  <tt>Float</tt> objects represent real numbers using the native
  architecture's double-precision floating point representation.  
<p/>
  <methods type="instance">
        <method name="Arithmetic operations" ref="Arithmeticoperations">
      <callseq>
<p/>
      </callseq>
      <desc>
<p/>
      Performs various arithmetic operations on <obj>flt</obj>.                                    
<p/>
      <table>
<tr>
  <td><obj>flt</obj></td>
  <td>+</td>
  <td><obj>aNumeric</obj></td>
  <td>Addition</td>
</tr>
<tr>
  <td><obj>flt</obj></td>
  <td>--</td>
  <td><obj>aNumeric</obj></td>
  <td>Subtraction</td>
</tr>
<tr>
  <td><obj>flt</obj></td>
  <td>*</td>
  <td><obj>aNumeric</obj></td>
  <td>Multiplication</td>
</tr>
<tr>
  <td><obj>flt</obj></td>
  <td>/</td>
  <td><obj>aNumeric</obj></td>
  <td>Division</td>
</tr>
<tr>
  <td><obj>flt</obj></td>
  <td>%</td>
  <td><obj>aNumeric</obj></td>
  <td>Modulo</td>
</tr>
<tr>
  <td><obj>flt</obj></td>
  <td>**</td>
  <td><obj>aNumeric</obj></td>
  <td>Exponentiation</td>
</tr>
</table>
<p/>
      </desc>
    </method>
<p/>
        <method name="&lt;=&gt;" ref="_lt_eq_lt">
      <callseq>
        <obj>flt</obj> &lt;=&gt; <obj>aNumeric</obj>
        <returns>-1, 0, +1</returns>
      </callseq>
      <desc>
<p/>
      Returns -1, 0, or +1 depending on whether <obj>flt</obj> is less
      than, equal to, or greater than <obj>aNumeric</obj>. This is the
      basis for the tests in <tt>Comparable</tt>.
<p/>
      </desc>
    </method>
<p/>
        <method name="ceil" ref="ceil">
      <callseq>
        <obj>flt</obj>.ceil <returns><obj>anInteger</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns the smallest <tt>Integer</tt> greater than or equal to <obj>flt</obj>.
<p/>
<codefragment>
<fullcode><![CDATA[        1.2.ceil
        2.0.ceil
        (-1.2).ceil
        (-2.0).ceil
]]></fullcode><rubycode>
<tr>
  <td><tt>1.2.ceil</tt></td>
  <td>&#187;</td>
  <td><tt>2</tt></td>
</tr>
<tr>
  <td><tt>2.0.ceil</tt></td>
  <td>&#187;</td>
  <td><tt>2</tt></td>
</tr>
<tr>
  <td><tt>(-1.2).ceil</tt></td>
  <td>&#187;</td>
  <td><tt>-1</tt></td>
</tr>
<tr>
  <td><tt>(-2.0).ceil</tt></td>
  <td>&#187;</td>
  <td><tt>-2</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
        <method name="finite?" ref="finite_qm">
      <callseq>
        <obj>flt</obj>.finite? <returns><const>true</const> or <const>false</const></returns>
      </callseq>
      <desc>
<p/>
      Returns <const>true</const> if <obj>flt</obj> is a valid IEEE floating point
      number (it is not infinite, and <meth>nan?</meth> is <const>false</const>).
<p/>
      </desc>
    </method>
<p/>
        <method name="floor" ref="floor">
      <callseq>
        <obj>flt</obj>.floor <returns><obj>anInteger</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns the largest integer less than or equal to <obj>flt</obj>.
<p/>
<codefragment>
<fullcode><![CDATA[        1.2.floor
        2.0.floor
        (-1.2).floor
        (-2.0).floor
]]></fullcode><rubycode>
<tr>
  <td><tt>1.2.floor</tt></td>
  <td>&#187;</td>
  <td><tt>1</tt></td>
</tr>
<tr>
  <td><tt>2.0.floor</tt></td>
  <td>&#187;</td>
  <td><tt>2</tt></td>
</tr>
<tr>
  <td><tt>(-1.2).floor</tt></td>
  <td>&#187;</td>
  <td><tt>-2</tt></td>
</tr>
<tr>
  <td><tt>(-2.0).floor</tt></td>
  <td>&#187;</td>
  <td><tt>-2</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
        <method name="infinite?" ref="infinite_qm">
      <callseq>
        <obj>flt</obj>.infinite? <returns><tt>nil</tt>, -1,
          +1</returns>
      </callseq>
      <desc>
<p/>
      Returns <tt>nil</tt>, -1, or +1 depending on whether <obj>flt</obj> is finite,
      -infinity, or +infinity.
<p/>
<codefragment>
<fullcode><![CDATA[        (0.0).infinite?
        (-1.0/0.0).infinite?
        (+1.0/0.0).infinite?
]]></fullcode><rubycode>
<tr>
  <td><tt>(0.0).infinite?</tt></td>
  <td>&#187;</td>
  <td><tt>nil</tt></td>
</tr>
<tr>
  <td><tt>(-1.0/0.0).infinite?</tt></td>
  <td>&#187;</td>
  <td><tt>-1</tt></td>
</tr>
<tr>
  <td><tt>(+1.0/0.0).infinite?</tt></td>
  <td>&#187;</td>
  <td><tt>1</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
        <method name="nan?" ref="nan_qm">
      <callseq>
        <obj>flt</obj>.nan? <returns><const>true</const> or <const>false</const></returns>
      </callseq>
      <desc>
<p/>
      Returns <const>true</const> if <obj>flt</obj> is an invalid IEEE
      floating point number.
<p/>
<codefragment>
<fullcode><![CDATA[        a = -1.0
        a.nan?
        a = Math.log(a)
        a.nan?
]]></fullcode><rubycode>
<tr>
  <td><tt>a<nbsp/>=<nbsp/>-1.0</tt></td>
  <td>&#187;</td>
  <td><tt>-1.0</tt></td>
</tr>
<tr>
  <td><tt>a.nan?</tt></td>
  <td>&#187;</td>
  <td><tt>false</tt></td>
</tr>
<tr>
  <td><tt>a<nbsp/>=<nbsp/>Math.log(a)</tt></td>
  <td>&#187;</td>
  <td><tt>NaN</tt></td>
</tr>
<tr>
  <td><tt>a.nan?</tt></td>
  <td>&#187;</td>
  <td><tt>true</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
        <method name="round" ref="round">
      <callseq>
        <obj>flt</obj>.round <returns><obj>anInteger</obj></returns>
      </callseq>
      <desc>
<p/>
      Rounds <obj>flt</obj> to the nearest integer. Equivalent to:
<p/>
<codefragment>
<alltt><fullcode><![CDATA[        def round
          return floor(self+0.5) if self > 0.0
          return ceil(self-0.5)  if self < 0.0
          return 0.0
        end
]]></fullcode>
def<nbsp/>round
<nbsp/><nbsp/>return<nbsp/>floor(self+0.5)<nbsp/>if<nbsp/>self<nbsp/>&gt;<nbsp/>0.0
<nbsp/><nbsp/>return<nbsp/>ceil(self-0.5)<nbsp/><nbsp/>if<nbsp/>self<nbsp/>&lt;<nbsp/>0.0
<nbsp/><nbsp/>return<nbsp/>0.0
end
</alltt>
</codefragment>
<p/>
<codefragment>
<fullcode><![CDATA[        1.5.round
        (-1.5).round
]]></fullcode><rubycode>
<tr>
  <td><tt>1.5.round</tt></td>
  <td>&#187;</td>
  <td><tt>2</tt></td>
</tr>
<tr>
  <td><tt>(-1.5).round</tt></td>
  <td>&#187;</td>
  <td><tt>-2</tt></td>
</tr>
</rubycode>
<p/>
</codefragment>
<p/>
      </desc>
    </method>
<p/>
        <method name="to_f" ref="to_f">
      <callseq>
        <obj>flt</obj>.to_f <returns><obj>flt</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns <obj>flt</obj>.
<p/>
      </desc>
    </method>
<p/>
        <method name="to_i" ref="to_i">
      <callseq>
        <obj>flt</obj>.to_i <returns><obj>anInteger</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns <obj>flt</obj> truncated to an <tt>Integer</tt>.
<p/>
      </desc>
    </method>
<p/>
        <method name="to_s" ref="to_s">
      <callseq>
        <obj>flt</obj>.to_s <returns><obj>aString</obj></returns>
      </callseq>
      <desc>
<p/>
      Returns a string containing a representation of self. As well as
      a fixed or exponential form of the number, the call may return
      ``<tt>NaN</tt>'', ``<tt>Infinity</tt>'', and ``<tt>-Infinity</tt>''.
<p/>
      </desc>
    </method>
<p/>
  </methods>
<p/>
</class>
</ppdoc>
