// envuse.java
// generic environmental use
// adapted from a program in basic by H.T. Odum & E. Odum, 1994.

import java.applet.Applet;
import java.awt.*;

public class envuse extends Applet
{

 Label prompt1,prompt2,prompt3;
 TextField input1,input2,input3;
 int t;
 double i,d,it;
 double jl,pi,pe,q,m,a,z,r;
 double dt,dq,da,dm,dd;
 double t0,q0,a0,m0,d0;
 double k0,k1,k2,k3,k4,k5,k6,k7,k8,k9,l1,l2;
 Button drawbutton;

 public void init()
 {
	prompt1 = new Label("I Environmental inputs: ");
	input1 = new TextField("10",4);
	add(prompt1);add(input1);

	prompt2 = new Label("                   IT Interest rate: ");
	input2 = new TextField("1",4);
	add(prompt2);add(input2);

	prompt3 = new Label("               D Debt ");
	input3 = new TextField("0",4);
	add(prompt3);add(input3);

	drawbutton = new Button("Draw"); add(drawbutton);
 }

 public boolean action(Event e, Object o)
 {
  i=0.1*(float)Integer.parseInt(input1.getText());
	it=0.1*(float)Integer.parseInt(input2.getText());
	d=(float)Integer.parseInt(input3.getText());
	repaint();
	return true;
 }

 public void paint(Graphics g)
 {
	g.drawRect(0,90,320,210);
	g.drawLine(0,190,320,190);
	t=0;
  k0=9; k1=0.5; k2=0.05; k3=0.6; k4=15; k5=0.8; k6=0.06; k7=0.6; k8=0; k9=0.1;
	l1=0.4; l2=2;
	dt=0.1;
	t0=10; q0=66.7; a0=20; m0=10; d0=10;
	jl=0.3; pi=10; pe=1; q=1; m=0.1; a=0.2; z=1;

	do
	{
	 g.setColor(Color.blue);
	 if (300-q*q0>190)	 g.drawOval(t,(int)(300-q*q0),1,1);
	 else
	 g.drawOval(t,190,1,1);

	 g.setColor(Color.green);
	 if (300-a*a0>190) g.drawOval(t,(int)(300-a*a0),1,1);
	 else
	 g.drawOval(t,190,1,1);

	 g.setColor(Color.red);
	 if (190-d*d0>90) g.drawOval(t,(int)(190-d*d0),1,1);
	 else
	 g.drawOval(t,90,1,1);

	 g.setColor(Color.yellow);
	 if (190-m*m0>90) g.drawOval(t,(int)(190-m*m0),1,1);
	 else
	 g.drawOval(t,90,1,1);

	 r=i/(1+k0);
	 pe=(l1+q)/(l2*q);
	 if (pe>3) pe=3;
	 if (d==0) z=0;
	 else z=1;
	 dq=k1*r-k2*q-k3*q*a;
	 da=k5*m/pi-k6*a-k7*q*a;
	 dm=pe*k4*a*q+jl-k5*m-it*d-z*k9*m;
	 dd=jl-z*k9*m;
	 a=a+da*dt;
	 if (a<0) a=0;
	 q=q+dq*dt;
	 if (q<0) q=0.0000000001;
	 m=m+dm*dt;
	 if (m<0) m=0;
	 d=d+dd*dt;
	 if (d<0) d=0;
	 t=t+1;
	 g.setColor(Color.black);
	 g.drawLine(0,190,320,190);
	}
	while (t<320);
 }
}
// Camila Duarte & e. Ortega. January 31th, 2001