<doc>

<legacy_id>1410</legacy_id>

<name>atan2</name>

<type>function</type>

<syntax>

<example>atan2(<i>yCoordinate</i>,<i>xCoordinate</i>)</example>

</syntax>

<library></library>

<objects>

</objects>

<synonyms>

</synonyms>

<classification>

<category>Math, Logic, &amp; Dates</category>

</classification>

<references>

<constant tag="pi">pi Constant</constant>

</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 arc tangent of one number divided by another, using the <glossary tag="sign">sign</glossary> of both.</summary>

<examples>

<example>atan2(-1,-1) <i>-- returns 4/3 * pi</i></example>

<example>atan2(thisNumber,thatNumber)</example>

</examples>

<description>

<p>Use the <b>atan2</b> <control_st tag="function">function</control_st> to find the arc tangent of one number divided by another when <glossary tag="sign">sign</glossary> is significant.</p><p/><p><b>Parameters:</b></p><p>The <i>yCoordinate</i> is a number or an <glossary tag="expression">expression</glossary> that <glossary tag="evaluate">evaluates</glossary> to a number.</p><p/><p>The <i>xCoordinate</i> is a number or an <glossary tag="expression">expression</glossary> that <glossary tag="evaluate">evaluates</glossary> to a number.</p><p/><p><b>Value:</b></p><p>The <b>atan2</b> <control_st tag="function">function</control_st> <glossary tag="return">returns</glossary> a number between -pi and pi.</p><p/><p><b>Comments:</b></p><p>In most cases, atan2(y,x) is equal to atan(y/x). However, if both x and y are negative, the sign of x/y is positive. In this case, the <b>atan</b> function <glossary tag="return">returns</glossary> an angle in the first quadrant, but the <b>atan2</b> <control_st tag="function">function</control_st> <glossary tag="return">returns</glossary> an angle in the third quadrant.</p><p/><p>The result of the <b>atan2</b> <control_st tag="function">function</control_st> is <glossary tag="return">returned</glossary> in <glossary tag="radian">radians</glossary>. To get this result in <glossary tag="degree">degrees</glossary>, use the following <href tag="dictionary/property/2381.xml">custom function</href>:</p><p/><p> function atan2InDegrees firstArg,secondArg</p><p> return atan2(firstArg,secondArg) * 180 / pi</p><p> end atan2InDegrees</p>

</description>

</doc>