public class PointCP

$\{$

$//$Instance variables $************************************************$

$/**$

$*$ Contains C$($artesian$)$ or P$($olar$)$ to identify the type of

$*$ coordinates that are being dealt with.

$*/$

private char typeCoord;

$/**$

$*$ Contains the current value of X or RHO depending on the type

$*$ of coordinates.

$*/$

private double xOrRho;

$/**$

$*$ Contains the current value of Y or THETA value depending on the

$*$ type of coordinates.

$*/$

private double yOrTheta;

$//$Constructors $******************************************************$

$/**$

$*$ Constructs a coordinate object, with a type identifier.

$*/$

public PointCP$($char type, double xOrRho, double yOrTheta$)$

$\{$

if$($type $!=\text{'}$C$\text{'}$ && type $!=\text{'}$P$\text{'})$

throw new IllegalArgumentException$()$;

this.xOrRho $=$ xOrRho;

this.yOrTheta $=$ yOrTheta;

typeCoord $=$ type;

$\}$

$//$Instance methods $**************************************************$

public double getX$()$

$\{$

if$($typeCoord $==\text{'}$C$\text{'})$

return xOrRho;

else

return $($Math$.$cos$($Math$.$toRadians$($yOrTheta$))*$ xOrRho$)$;

$\}$

public double getY$()$

$\{$

if$($typeCoord $==\text{'}$C$\text{'})$

return yOrTheta;

else

return $($Math$.$sin$($Math$.$toRadians$($yOrTheta$))*$ xOrRho$)$;

$\}$

public double getRho$()$

$\{$

if$($typeCoord $==\text{'}$P$\text{'})$

return xOrRho;

else

return $($Math$.$sqrt$($Math$.$pow$($xOrRho$,2)+$ Math.pow$($yOrTheta$,2)))$;

$\}$

public double getTheta$()$

$\{$

if$($typeCoord $==\text{'}$P$\text{'})$

return yOrTheta;

else

return Math.toDegrees$($Math$.$atan$2($yOrTheta$,$ xOrRho$))$;

$\}$

$/**$

$*$ Converts Cartesian coordinates to Polar coordinates.

$*/$

public void convertStorageToPolar$()$

$\{$

if$($typeCoord $!=\text{'}$P$\text{'})$

$\{$

$//$Calculate RHO and THETA

double temp $=$ getRho$()$;

yOrTheta $=$ getTheta$()$;

xOrRho $=$ temp;

typeCoord $=\text{'}$P$\text{'}$; $//$Change coord type identifier

$\}$

$\}$

$/**$

$*$ Converts Polar coordinates to Cartesian coordinates.

$*/$

public void convertStorageToCartesian$()$

$\{$

if$($typeCoord $!=\text{'}$C$\text{'})$

$\{$

$//$Calculate X and Y

double temp $=$ getX$()$;

yOrTheta $=$ getY$()$;

xOrRho $=$ temp;

typeCoord $=\text{'}$C$\text{'}$; $//$Change coord type identifier

$\}$

$\}$

$/**$

$*$ Calculates the distance in between two points using the Pythagorean

$*$ theorem $($C $^2=$ A $^2+$ B $^2).$ Not needed until E$2\mathrm{.}30.$

$*$

$*$ @param pointA The first point.

$*$ @param pointB The second point.

$*$ @return The distance between the two points.

$*/$

public double getDistance$($PointCP pointB$)$

$\{$

$//$ Obtain differences in X and Y$,$ sign is not important as these values

$//$ will be squared later.

double deltaX $=$ getX$()-$ pointB.getX$()$;

double deltaY $=$ getY$()-$ pointB.getY$()$;

return Math.sqrt$(($Math$.$pow$($deltaX$,2)+$ Math.pow$($deltaY$,2)))$;

$\}$

$/**$

$*$ Rotates the specified point by the specified number of degrees.

$*$ Not required until E$2\mathrm{.}30$

$*$

$*$ @param point The point to rotate

$*$ @param rotation The number of degrees to rotate the point.

$*$ @return The rotated image of the original point.

$*/$

public PointCP rotatePoint$($double rotation$)$

$\{$

double radRotation $=$ Math.toRadians$($rotation$)$;

double X $=$ getX$()$;

double Y $=$ getY$()$;

return new PointCP$(\text{'}$C$\text{'},$

$($Math$.$cos$($radRotation$)*$ X$)-($Math$.$sin$($radRotation$)*$ Y$),$

$($Math$.$sin$($radRotation$)*$ X$)+($Math$.$cos$($radRotation$)*$ Y$))$;

$\}$

$/**$

$*$ Returns information about the coordinates.

$*$

$*$ @return A String containing information about the coordinates.

$*/$

public String toString$()$

$\{$

return "Stored as $"+($typeCoord $==\text{'}$C$\text{'}$

$?$ "Cartesian $("+$ getX$()+","+$ getY$()+")"$

: "Polar $["+$ getRho$()+","+$ getTheta$()+"]")+"$

$"$;$\}\}$ this is pointcp.java file public class PointCPTest

$\{$

$//$Class methods $*****************************************************$

$/**$

$*$ This method is responsible for the creation of the PointCP

$*$ object. This can be done in two ways; the first, by using the

$*$ command line and running the program using java

$*$ PointCPTest

$*$ and the second by getting the program to prompt the user.

$*$ If the user does not enter a valid sequence at the command line,

$*$ the program will prompte him or her.

$*$

$*$ @param args$[0]$ The coordinate type. P for polar and C for

$*$ cartesian.

$*$ @param args$[1]$ The value of X or RHO.

$*$ @param args$[2]$ The value of Y or THETA.

$*/$

public static void main$($String$[]$ args$)$

$\{$

PointCP point;

System.out.println$("$Cartesian$-$Polar Coordinates Conversion Program"$)$;

$//$ Check if the user input coordinates from the command line

$//$ If he did, create the PointCP object from these arguments.

$//$ If he did not, prompt the user for them.

try

$\{$

point $=$ new PointCP$($args$[0].$toUpperCase$().$charAt$(0),$

Double.valueOf$($args$[1]).$doubleValue$(),$ this is pointcp testImplementation of D