xdocs/userguide/complex.xml - commons-math - Git at Google

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 <!-- $Revision$ $Date$ -->
 <document url="stat.html">
   <properties>
     <title>The Commons Math User Guide - Statistics</title>
   </properties>
   <body>
     <section name="7 Complex Numbers">
       <subsection name="7.1 Overview" href="overview">
         <p>
           The complex packages provides a complex number type as well as complex
           versions of common transcendental functions and complex number
           formatting.
         </p>
       </subsection>
       <subsection name="7.2 Complex Numbers" href="complex">
         <p>
           <a href="../apidocs/org/apache/commons/math/complex/Complex.html">
           org.apache.commons.math.complex.Complex</a> provides a complex number
           type that forms the basis for the complex functionality found in
           commons-math.
         </p>
         <p>
           To create a complex number, simply call the constructor passing in two
           floating-point arguments, the first being the real part of the
           complex number and the second being the imaginary part:
           <source>Complex c = new Complex(1.0, 3.0); // 1 + 3i</source>
         </p>
         <p>
           The <code>Complex</code> class provides many unary and binary
           complex number operations.  These operations provide the means to add,
           subtract, multiple and, divide complex numbers along with other
           complex number functions similar to the real number functions found in
           <code>java.math.BigDecimal</code>:
           <source>Complex lhs = new Complex(1.0, 3.0);
 Complex rhs = new Complex(2.0, 5.0);

 Complex answer = lhs.add(rhs);       // add two complex numbers
         answer = lhs.subtract(rhs);  // subtract two complex numbers
         answer = lhs.abs();          // absolute value
         answer = lhs.conjugate(rhs); // complex conjugate</source>
         </p>
       </subsection>
       <subsection name="7.3 Complex Transcendental Functions" href="function">
         <p>
           <a href="../apidocs/org/apache/commons/math/complex/ComplexUtils.html">
           org.apache.commons.math.complex.ComplexMath</a> provides
           implementations of serveral transcendental functions involving complex
           number arguments.  These operations provide the means to compute the
           log, sine, tangent and, other complex values similar to the real
           number functions found in <code>java.lang.Math</code>:
           <source>Complex first = new Complex(1.0, 3.0);
 Complex second = new Complex(2.0, 5.0);

 Complex answer = ComplexMath.log(first);          // natural logarithm.
         answer = ComplexMath.cos(first);          // cosine
         answer = ComplexMath.pow(first, second);  // first raised to the power of second</source>
         </p>
       </subsection>
       <subsection name="7.4 Complex Formatting and Parsing" href="formatting">
         <p>
           <code>Complex</code> instances can be converted to and from strings
           using the<a href="../apidocs/org/apache/commons/math/complex/ComplexFormat.html">
           org.apache.commons.math.complex.ComplexFormat</a> class.
           <code>ComplexFormat</code> is a <code>java.text.Format</code>
           extension and, as such, is used like other formatting objects (e.g.
           <code>java.text.SimpleDateFormat</code>):
           <source>ComplexFormat format = new ComplexFormat(); // default format
 Complex c = new Complex(1.1111, 2.2222);
 String s = format.format(c); // s contains "1.11 + 2.22i"</source>
         </p>
         <p>
           To customize the formatting output, one or two
           <code>java.text.NumberFormat</code> instances can be used to construct
           a <code>ComplexFormat</code>.  These number formats control the
           formatting of the real and imaginary values of the complex number:
           <source>NumberFormat nf = NumberFormat.getInstance();
 nf.setMinimumFractionDigits(3);
 nf.setMaximumFractionDigits(3);

 // create complex format with custom number format
 // when one number format is used, both real and
 // imaginary parts are formatted the same
 ComplexFormat cf = new ComplexFormat(nf);
 Complex c = new Complex(1.11, 2.2222);
 String s = format.format(c); // s contains "1.110 + 2.222i"

 NumberFormat nf2 = NumberFormat.getInstance();
 nf.setMinimumFractionDigits(1);
 nf.setMaximumFractionDigits(1);

 // create complex format with custom number formats
 cf = new ComplexFormat(nf, nf2);
 s = format.format(c); // s contains "1.110 + 2.2i"</source>
         </p>
         <p>
           Another formatting customization provided by
           <code>ComplexFormat</code> is the text used for the imaginary
           designation.  By default, the imaginary notation is "i" but, it can be
           manipulated using the <code>setImaginaryCharacter</code> method.
         </p>
         <p>
           Formatting inverse operation, parsing, can also be performed by
           <code>ComplexFormat</code>.  Parse a complex number from a string,
           simply call the <code>parse</code> method:
           <source>ComplexFormat cf = new ComplexFormat();
 Complex c = cf.parse("1.110 + 2.222i");</source>
         </p>
       </subsection>
     </section>
   </body>
 </document>
	<?xml version="1.0"?>

	<!--
	Copyright 2003-2004 The Apache Software Foundation

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	-->

	<?xml-stylesheet type="text/xsl" href="./xdoc.xsl"?>
	<!-- $Revision$ $Date$ -->
	<document url="stat.html">
	<properties>
	<title>The Commons Math User Guide - Statistics</title>
	</properties>
	<body>
	<section name="7 Complex Numbers">
	<subsection name="7.1 Overview" href="overview">
	<p>
	The complex packages provides a complex number type as well as complex
	versions of common transcendental functions and complex number
	formatting.
	</p>
	</subsection>
	<subsection name="7.2 Complex Numbers" href="complex">
	<p>
	<a href="../apidocs/org/apache/commons/math/complex/Complex.html">
	org.apache.commons.math.complex.Complex</a> provides a complex number
	type that forms the basis for the complex functionality found in
	commons-math.
	</p>
	<p>
	To create a complex number, simply call the constructor passing in two
	floating-point arguments, the first being the real part of the
	complex number and the second being the imaginary part:
	<source>Complex c = new Complex(1.0, 3.0); // 1 + 3i</source>
	</p>
	<p>
	The <code>Complex</code> class provides many unary and binary
	complex number operations. These operations provide the means to add,
	subtract, multiple and, divide complex numbers along with other
	complex number functions similar to the real number functions found in
	<code>java.math.BigDecimal</code>:
	<source>Complex lhs = new Complex(1.0, 3.0);
	Complex rhs = new Complex(2.0, 5.0);

	Complex answer = lhs.add(rhs); // add two complex numbers
	answer = lhs.subtract(rhs); // subtract two complex numbers
	answer = lhs.abs(); // absolute value
	answer = lhs.conjugate(rhs); // complex conjugate</source>
	</p>
	</subsection>
	<subsection name="7.3 Complex Transcendental Functions" href="function">
	<p>
	<a href="../apidocs/org/apache/commons/math/complex/ComplexUtils.html">
	org.apache.commons.math.complex.ComplexMath</a> provides
	implementations of serveral transcendental functions involving complex
	number arguments. These operations provide the means to compute the
	log, sine, tangent and, other complex values similar to the real
	number functions found in <code>java.lang.Math</code>:
	<source>Complex first = new Complex(1.0, 3.0);
	Complex second = new Complex(2.0, 5.0);

	Complex answer = ComplexMath.log(first); // natural logarithm.
	answer = ComplexMath.cos(first); // cosine
	answer = ComplexMath.pow(first, second); // first raised to the power of second</source>
	</p>
	</subsection>
	<subsection name="7.4 Complex Formatting and Parsing" href="formatting">
	<p>
	<code>Complex</code> instances can be converted to and from strings
	using the<a href="../apidocs/org/apache/commons/math/complex/ComplexFormat.html">
	org.apache.commons.math.complex.ComplexFormat</a> class.
	<code>ComplexFormat</code> is a <code>java.text.Format</code>
	extension and, as such, is used like other formatting objects (e.g.
	<code>java.text.SimpleDateFormat</code>):
	<source>ComplexFormat format = new ComplexFormat(); // default format
	Complex c = new Complex(1.1111, 2.2222);
	String s = format.format(c); // s contains "1.11 + 2.22i"</source>
	</p>
	<p>
	To customize the formatting output, one or two
	<code>java.text.NumberFormat</code> instances can be used to construct
	a <code>ComplexFormat</code>. These number formats control the
	formatting of the real and imaginary values of the complex number:
	<source>NumberFormat nf = NumberFormat.getInstance();
	nf.setMinimumFractionDigits(3);
	nf.setMaximumFractionDigits(3);

	// create complex format with custom number format
	// when one number format is used, both real and
	// imaginary parts are formatted the same
	ComplexFormat cf = new ComplexFormat(nf);
	Complex c = new Complex(1.11, 2.2222);
	String s = format.format(c); // s contains "1.110 + 2.222i"

	NumberFormat nf2 = NumberFormat.getInstance();
	nf.setMinimumFractionDigits(1);
	nf.setMaximumFractionDigits(1);

	// create complex format with custom number formats
	cf = new ComplexFormat(nf, nf2);
	s = format.format(c); // s contains "1.110 + 2.2i"</source>
	</p>
	<p>
	Another formatting customization provided by
	<code>ComplexFormat</code> is the text used for the imaginary
	designation. By default, the imaginary notation is "i" but, it can be
	manipulated using the <code>setImaginaryCharacter</code> method.
	</p>
	<p>
	Formatting inverse operation, parsing, can also be performed by
	<code>ComplexFormat</code>. Parse a complex number from a string,
	simply call the <code>parse</code> method:
	<source>ComplexFormat cf = new ComplexFormat();
	Complex c = cf.parse("1.110 + 2.222i");</source>
	</p>
	</subsection>
	</section>
	</body>
	</document>