Translate the code from the BASIC idiom to Java and then compile and run. You sh

Question

 Translate the code from the BASIC idiom to Java and then compile and run. You should see a Rainbow gradually appearing, point by point, in the Display window.     /*   Notes:    PRINT becomes system.out.println ( ) ;   PRINT USING is formatted output, you can likely ignore the formatting   REM is a comment   INPUT is a combination of System.out.println ( prompt) then use a Scanner     to getNext ( ) the needed value.   ^ means exponentiation, or "raising to a power"   : allows multiple BASIC statements on the same line.   GOSUB was a way to run a function. */  // Global floating points -- like BASIC float R, RC, R0, X, Y, B, C, N, I, T1, T2, RS, RP, RB, Rc, I1, I2, TH ; int NP = 0 ;  // REM     PLOT ON SCREEN void plot ( ) {   /* 180 REM     PLOT ON SCREEN   185 TH=ABS(TH)   190 IF TH>60 THEN RETURN   195 XP=320+320*(TH/60)*(X/B)   200 YP=325-300*(TH/60)*ABS(Y/B)   205 PSET(XP,YP),C:  NP=NP+1   210 LOCATE 1,1:  PRINT NP:  RETURN   */   if ( TH > 60.0 )   {     return ;   }   float XP=139+139*(TH/60)*(X/B) ;   float YP=159-159*(TH/60)*abs(Y/B) ;   stroke ( C, 100, 100 ) ;   point( XP + 300, 600 - YP ) ;   NP ++ ;   println ( NP + "," + XP + "," + YP + "," + C ) ;   return ;  }  void setup ( ) {   size ( 900, 600 ) ;   background ( 0 ) ;    // https://processing.org/reference/colorMode_.html   colorMode(HSB, 100); }  void draw ( ) {   // Convert this BASIC to Java here:   // Notes: for gosub 180, use   // plot ( ) ;   //   // for the goto 30, use a do/while loop   //   // find Java/Processing equivalents for ATN, SIN, SQR, RND and ^   /*   25 R0=180/3.14159   30 REM     RANDOM IMPACT PARAMETER   35 X=-1+2*RND(1)   40 Y=-1+2*RND(1)   45 B=SQR(X*X+Y*Y)   50 IF B>=1 THEN 30   55 REM     COLOR & INDEX OF REFR.   60 C=1+INT(3*RND(1))   65 N=1.33+.01*(C-1)   70 REM     COMPUTE ANGLES   75 I=ATN(B/SQR(1-B*B))   80 R=ATN(B/SQR(N*N-B*B))   85 T1=(4*R-2*I)*R0   90 T2=(6*R-2*I)*R0-180   95 REM     INTENSITY FACTORS   100 RS=(SIN(I-R)/SIN(I+R))^2   105 RP=(TAN(I-R)/TAN(I+R))^2   110 RB=(1-RP)*(1-RP)   115 RC=(1-RS)*(1-RS)   120 I1=(RS*RC+RP*RB)/2   125 I2=(RS*RS*RC+RP*RP*RB)/2   130 IF I1<.04*RND(1) THEN 140   135 TH=T1:  GOSUB 180   140 IF I2<.02*RND(1) THEN 150   145 TH=T2:  GOSUB 180   150 GOTO 30   */ } 

Explanation / Answer

import java.io.*;
import java.awt.Graphics;

import java.awt.Container;

import java.awt.Color;

public class Rainbow {

public static void main(String[] args) {

int n = Integer.parseInt(args[0]);
int SIZE = 1000;
StdDraw.setCanvasSize(SIZE, SIZE/2);
StdDraw.setXscale(0, SIZE);
StdDraw.setYscale(0, SIZE/2.0);
StdDraw.enableDoubleBuffering();

for (int i = 0; i < n; i++) {

// generate random (x, y) uniformly in unit circle centered at (0, 0)
double r = Math.random();   
double theta = Math.random() * 2 * Math.PI;   
double x = Math.sqrt(r) * Math.sin(theta);
double y = Math.sqrt(r) * Math.cos(theta);

float c = (float) Math.random();   
double n = 1.33 + 0.06 * c; // refraction index

double thetaI = Math.asin(r);   
double thetaR = Math.asin(r / n);   
double thetaP = 4*thetaR - 2*thetaI; // primary rainbow angle
double thetaS = 6*thetaR - 2*thetaI - Math.PI; // secondary rainbow angle

double p = Math.pow(Math.sin(thetaI - thetaR) / Math.sin(thetaI + thetaR),2);

double s = Math.pow(Math.tan(thetaI - thetaR) / Math.tan(thetaI + thetaR), 2);
double intensityP = 0.5 * ( s*(1-s)*(1-s) + p*(1-p)*(1-p));
double intensityS = 0.5 * (s*s*(1-s)*(1-s) + p*p*(1-p)*(1-p));

// plot primary rainbow
float saturation = (float) Math.min(intensityP / 0.04, 1.0);
StdDraw.setPenColor(Color.getHSBColor(c, saturation, 1.0f));
double xp = (SIZE/2.0 * thetaP * 3 / Math.PI * x / r) + SIZE / 2.0;
double yp = (SIZE/2.0 * thetaP * 3 / Math.PI * Math.abs(y) / r);
StdDraw.point(xp, yp);

// plot secondary rainbow
saturation = (float) Math.min(intensityS / 0.02, 1.0);
StdDraw.setPenColor(Color.getHSBColor(c, saturation, 1.0f));
double xs = ( SIZE/2.0 * thetaS * 3 / Math.PI * x / r) + SIZE / 2.0;
double ys = (-SIZE/2.0 * thetaS * 3 / Math.PI * Math.abs(y) / r);
StdDraw.point(xs, ys);

// display every 1000 iterates
if (i % 1000 == 0) {
StdDraw.show();
StdDraw.pause(10);
}
}

StdDraw.show();
}

}

I have written the code as above.

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