Java是否有复杂数字的类？

Java是否有复杂数字的类？

Answer 1

有一个名为Complex的Apache Commons 。 我不相信JDK有一个。

Answer 2

不幸的是，JDK目前​​没有任何复数类。

你可以看看：

http://www.java2s.com/Code/Java/Data-Type/Thisclassrepresentscomplexnumbersanddefinesmethodsforperformingarithmeticoncomplexnumbers.htm

它提供了一个您可能会觉得有用的实现。

Answer 3

不，JDK没有，但这是我编写的实现。

这是GITHUB项目。

 /** * ComplexNumber is a class which implements complex numbers in Java. * It includes basic operations that can be performed on complex numbers such as, * addition, subtraction, multiplication, conjugate, modulus and squaring. * The data type for Complex Numbers. * 

 * The features of this library include:
 * 
 * 
Arithmetic Operations (addition, subtraction, multiplication, division)
 * 
Complex Specific Operations - Conjugate, Inverse, Absolute/Magnitude, Argument/Phase
 * 
Trigonometric Operations - sin, cos, tan, cot, sec, cosec
 * 
Mathematical Functions - exp
 * 
Complex Parsing of type x+yi
 * 
 * * @author Abdul Fatir * @version 1.1 * */ public class ComplexNumber { /** * Used in format(int) to format the complex number as x+yi */ public static final int XY = 0; /** * Used in format(int) to format the complex number as R.cis(theta), where theta is arg(z) */ public static final int RCIS = 1; /** * The real, Re(z), part of the ComplexNumber. */ private double real; /** * The imaginary, Im(z), part of the ComplexNumber. */ private double imaginary; /** * Constructs a new ComplexNumber object with both real and imaginary parts 0 (z = 0 + 0i). */ public ComplexNumber() { real = 0.0; imaginary = 0.0; } /** * Constructs a new ComplexNumber object. * @param real the real part, Re(z), of the complex number * @param imaginary the imaginary part, Im(z), of the complex number */ public ComplexNumber(double real, double imaginary) { this.real = real; this.imaginary = imaginary; } /** * Adds another ComplexNumber to the current complex number. * @param z the complex number to be added to the current complex number */ public void add(ComplexNumber z) { set(add(this,z)); } /** * Subtracts another ComplexNumber from the current complex number. * @param z the complex number to be subtracted from the current complex number */ public void subtract(ComplexNumber z) { set(subtract(this,z)); } /** * Multiplies another ComplexNumber to the current complex number. * @param z the complex number to be multiplied to the current complex number */ public void multiply(ComplexNumber z) { set(multiply(this,z)); } /** * Divides the current ComplexNumber by another ComplexNumber. * @param z the divisor */ public void divide(ComplexNumber z) { set(divide(this,z)); } /** * Sets the value of current complex number to the passed complex number. * @param z the complex number */ public void set(ComplexNumber z) { this.real = z.real; this.imaginary = z.imaginary; } /** * Adds two ComplexNumber. * @param z1 the first ComplexNumber. * @param z2 the second ComplexNumber. * @return the resultant ComplexNumber (z1 + z2). */ public static ComplexNumber add(ComplexNumber z1, ComplexNumber z2) { return new ComplexNumber(z1.real + z2.real, z1.imaginary + z2.imaginary); } /** * Subtracts one ComplexNumber from another. * @param z1 the first ComplexNumber. * @param z2 the second ComplexNumber. * @return the resultant ComplexNumber (z1 - z2). */ public static ComplexNumber subtract(ComplexNumber z1, ComplexNumber z2) { return new ComplexNumber(z1.real - z2.real, z1.imaginary - z2.imaginary); } /** * Multiplies one ComplexNumber to another. * @param z1 the first ComplexNumber. * @param z2 the second ComplexNumber. * @return the resultant ComplexNumber (z1 * z2). */ public static ComplexNumber multiply(ComplexNumber z1, ComplexNumber z2) { double _real = z1.real*z2.real - z1.imaginary*z2.imaginary; double _imaginary = z1.real*z2.imaginary + z1.imaginary*z2.real; return new ComplexNumber(_real,_imaginary); } /** * Divides one ComplexNumber by another. * @param z1 the first ComplexNumber. * @param z2 the second ComplexNumber. * @return the resultant ComplexNumber (z1 / z2). */ public static ComplexNumber divide(ComplexNumber z1, ComplexNumber z2) { ComplexNumber output = multiply(z1,z2.conjugate()); double div = Math.pow(z2.mod(),2); return new ComplexNumber(output.real/div,output.imaginary/div); } /** * The complex conjugate of the current complex number. * @return a ComplexNumber object which is the conjugate of the current complex number */ public ComplexNumber conjugate() { return new ComplexNumber(this.real,-this.imaginary); } /** * The modulus, magnitude or the absolute value of current complex number. * @return the magnitude or modulus of current complex number */ public double mod() { return Math.sqrt(Math.pow(this.real,2) + Math.pow(this.imaginary,2)); } /** * The square of the current complex number. * @return a ComplexNumber which is the square of the current complex number. */ public ComplexNumber square() { double _real = this.real*this.real - this.imaginary*this.imaginary; double _imaginary = 2*this.real*this.imaginary; return new ComplexNumber(_real,_imaginary); } /** * @return the complex number in x + yi format */ @Override public String toString() { String re = this.real+""; String im = ""; if(this.imaginary < 0) im = this.imaginary+"i"; else im = "+"+this.imaginary+"i"; return re+im; } /** * Calculates the exponential of the ComplexNumber * @param z The input complex number * @return a ComplexNumber which is e^(input z) */ public static ComplexNumber exp(ComplexNumber z) { double a = z.real; double b = z.imaginary; double r = Math.exp(a); a = r*Math.cos(b); b = r*Math.sin(b); return new ComplexNumber(a,b); } /** * Calculates the ComplexNumber to the passed integer power. * @param z The input complex number * @param power The power. * @return a ComplexNumber which is (z)^power */ public static ComplexNumber pow(ComplexNumber z, int power) { ComplexNumber output = new ComplexNumber(z.getRe(),z.getIm()); for(int i = 1; i < power; i++) { double _real = output.real*z.real - output.imaginary*z.imaginary; double _imaginary = output.real*z.imaginary + output.imaginary*z.real; output = new ComplexNumber(_real,_imaginary); } return output; } /** * Calculates the sine of the ComplexNumber * @param z the input complex number * @return a ComplexNumber which is the sine of z. */ public static ComplexNumber sin(ComplexNumber z) { double x = Math.exp(z.imaginary); double x_inv = 1/x; double r = Math.sin(z.real) * (x + x_inv)/2; double i = Math.cos(z.real) * (x - x_inv)/2; return new ComplexNumber(r,i); } /** * Calculates the cosine of the ComplexNumber * @param z the input complex number * @return a ComplexNumber which is the cosine of z. */ public static ComplexNumber cos(ComplexNumber z) { double x = Math.exp(z.imaginary); double x_inv = 1/x; double r = Math.cos(z.real) * (x + x_inv)/2; double i = -Math.sin(z.real) * (x - x_inv)/2; return new ComplexNumber(r,i); } /** * Calculates the tangent of the ComplexNumber * @param z the input complex number * @return a ComplexNumber which is the tangent of z. */ public static ComplexNumber tan(ComplexNumber z) { return divide(sin(z),cos(z)); } /** * Calculates the co-tangent of the ComplexNumber * @param z the input complex number * @return a ComplexNumber which is the co-tangent of z. */ public static ComplexNumber cot(ComplexNumber z) { return divide(new ComplexNumber(1,0),tan(z)); } /** * Calculates the secant of the ComplexNumber * @param z the input complex number * @return a ComplexNumber which is the secant of z. */ public static ComplexNumber sec(ComplexNumber z) { return divide(new ComplexNumber(1,0),cos(z)); } /** * Calculates the co-secant of the ComplexNumber * @param z the input complex number * @return a ComplexNumber which is the co-secant of z. */ public static ComplexNumber cosec(ComplexNumber z) { return divide(new ComplexNumber(1,0),sin(z)); } /** * The real part of ComplexNumber * @return the real part of the complex number */ public double getRe() { return this.real; } /** * The imaginary part of ComplexNumber * @return the imaginary part of the complex number */ public double getIm() { return this.imaginary; } /** * The argument/phase of the current complex number. * @return arg(z) - the argument of current complex number */ public double getArg() { return Math.atan2(imaginary,real); } /** * Parses the String as a ComplexNumber of type x+yi. * @param s the input complex number as string * @return a ComplexNumber which is represented by the string. */ public static ComplexNumber parseComplex(String s) { s = s.replaceAll(" ",""); ComplexNumber parsed = null; if(s.contains(String.valueOf("+")) || (s.contains(String.valueOf("-")) && s.lastIndexOf('-') > 0)) { String re = ""; String im = ""; s = s.replaceAll("i",""); s = s.replaceAll("I",""); if(s.indexOf('+') > 0) { re = s.substring(0,s.indexOf('+')); im = s.substring(s.indexOf('+')+1,s.length()); parsed = new ComplexNumber(Double.parseDouble(re),Double.parseDouble(im)); } else if(s.lastIndexOf('-') > 0) { re = s.substring(0,s.lastIndexOf('-')); im = s.substring(s.lastIndexOf('-')+1,s.length()); parsed = new ComplexNumber(Double.parseDouble(re),-Double.parseDouble(im)); } } else { // Pure imaginary number if(s.endsWith("i") || s.endsWith("I")) { s = s.replaceAll("i",""); s = s.replaceAll("I",""); parsed = new ComplexNumber(0, Double.parseDouble(s)); } // Pure real number else { parsed = new ComplexNumber(Double.parseDouble(s),0); } } return parsed; } /** * Checks if the passed ComplexNumber is equal to the current. * @param z the complex number to be checked * @return true if they are equal, false otherwise */ @Override public final boolean equals(Object z) { if (!(z instanceof ComplexNumber)) return false; ComplexNumber a = (ComplexNumber) z; return (real == a.real) && (imaginary == a.imaginary); } /** * The inverse/reciprocal of the complex number. * @return the reciprocal of current complex number. */ public ComplexNumber inverse() { return divide(new ComplexNumber(1,0),this); } /** * Formats the Complex number as x+yi or r.cis(theta) * @param format_id the format ID ComplexNumber.XY or ComplexNumber.RCIS. * @return a string representation of the complex number * @throws IllegalArgumentException if the format_id does not match. */ public String format(int format_id) throws IllegalArgumentException { String out = ""; if(format_id == XY) out = toString(); else if(format_id == RCIS) { out = mod()+" cis("+getArg()+")"; } else { throw new IllegalArgumentException("Unknown Complex Number format."); } return out; } }