<doc>
  <legacy_id>2108</legacy_id>
  <name>log2</name>
  <type>function</type>
  <syntax>
    <example>the log2 of <i>number</i></example>
    <example>log2(<i>number</i>)</example>
  </syntax>
  <library></library>
  <objects>
  </objects>
  <synonyms>
  </synonyms>
  <classification>
    <category>Math, Logic, &amp; Dates</category>
  </classification>
  <references>
    <function tag="ln1">ln1 Function</function>
  </references>
  <history>
    <introduced version="1.0">Added.</introduced>
  </history>
  <platforms>
    <mac/>
    <windows/>
    <linux/>
    <ios/>
    <android/>
  </platforms>
  <classes>
    <desktop/>
    <server/>
    <web/>
    <mobile/>
  </classes>
  <security>
  </security>
  <summary><glossary tag="return">Returns</glossary> the base-2 logarithm of a number.</summary>
  <examples>
    <example>log2(8) <code><i>-- returns 3</i></code></example>
    <example>log2(0.125) <code><i>-- returns -3</i></code></example>
  </examples>
  <description>
    <p>Use the <b>log2</b> <control_st tag="function">function</control_st> to obtain a base-2 logarithm.</p><p/><p><b>Parameters:</b></p><p>The <i>number</i> is a positive number, or an <glossary tag="expression">expression</glossary> that <glossary tag="evaluate">evaluates</glossary> to a positive number.</p><p/><p><b>Value:</b></p><p>The <b>log2</b> function <glossary tag="return">returns</glossary> a number.</p><p/><p><b>Comments:</b></p><p>The base-2 logarithm of a <i>number</i> is the power to which 2 must be raised to obtain the <i>number</i>:<code> 2^log2(<i>number</i>) </code>is equal to <i>number.</i></p>
  </description>
</doc>