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/*File Circle02 Copyright 2016 R.G.Baldwin
********************************************************************/import java.awt.Color;
public class Circle02{//Driver classpublic static void main(String[] args){Circle02Runner obj = new Circle02Runner();
obj.run();}//end main
}//end class Circle02//=================================================================//
class Circle02Runner{//Instantiate the World and Turtle objects.
private World world = new World(300,300);private Turtle turtle = new Turtle(0,0,world);
//The following is new relative to Circle01private Picture pic = world.getPicture();
private Pixel pixel = null;//----------------------------------------------------//
public void run(){//Make the turtle invisible
turtle.hide();//Prepare the pen
turtle.setPenColor(Color.RED);turtle.setPenWidth(4);//Draw the axes in RED
turtle.penUp();turtle.moveTo(world.getWidth()/2,0);
turtle.penDown();turtle.moveTo(world.getWidth()/2,world.getHeight());
turtle.penUp();turtle.moveTo(world.getWidth(),world.getHeight()/2);
turtle.penDown();turtle.moveTo(0,world.getHeight()/2);
turtle.penUp();turtle.moveTo(0,0);//Prepare the variables
double xOff = -0.2;//offset relative to 1.0double yOff = -0.2;
double xScale = 1.0*world.getWidth()/2;double yScale = 1.0*world.getHeight()/2;
double rVal = 0.6;//radius relative to 1.0double yVal = 0;
int row = 0;int col = 0;
double xVal = -rVal;double xInc = 2*rVal/100;
turtle.setPenColor(Color.BLUE);//Draw the bottom half of the circle in BLUE.
for(int cnt=0; cnt<=100;cnt++,xVal += xInc){
//Get a y-value for the given x-value.yVal = function(rVal,xVal);
//Apply the offsets and scale the resultscol = (int)((xOff+xVal)*xScale);
row = (int)((yOff+yVal)*yScale);//The following is new relative to Circle01. Translate the// origin to the center and set the colors of specified
// pixels relative to the new origin.pixel = pic.getPixel(col + world.getWidth()/2,
row + world.getHeight()/2);pixel.setColor(Color.BLUE);
}//end for loop//Draw other half of the circle in greenturtle.setPenColor(Color.GREEN);
turtle.penUp();xVal = -rVal;
for(int cnt=0; cnt<=100;cnt++,xVal += xInc){
//Get a y-value for the given x-value.yVal = function(rVal,xVal);
//Apply the offsets and scale the results. Note the application// of a negative sign to yVal.
col = (int)((xOff+xVal)*xScale);row = (int)((yOff-yVal)*yScale);
//Move to the first point without drawing a line because the// pen is not down. Translate the origin to the center in the
// process.turtle.moveTo(col + world.getWidth()/2,
row + world.getHeight()/2);//Lower the pen in order to draw a line from each point to the
// next point.turtle.penDown();
}//end for loop}//end run method
//---------------------------------------------------------------////This method evaluates and returns the y-value for each x-value// for a circle with no offset centered at the origin.
// radius*radius = x*x + y*y//Note that the value returned from the sqrt method can be
// considered to be either positive or negative. Only the positive// value is returned.
double function(double rVal,double xVal){//Add a small positive fudge factor to prevent the value inside
// the radical from going negative due to small computational// errors when the radius and the xVal should be equal.
double yVal = Math.sqrt(rVal*rVal - xVal*xVal + 0.0000000001);return yVal;
}//end function//---------------------------------------------------------------//}//end class Circle02Runner /*File Cosine01 Copyright 2016 R.G.Baldwin
********************************************************************/import java.awt.Color;
public class Cosine01{//Driver classpublic static void main(String[] args){Cosine01Runner obj = new Cosine01Runner();
obj.run();}//end main
}//end class Cosine01//==================================================================/
class Cosine01Runner{//Instantiate the World and Turtle objects.
private World world = new World(300,300);private Turtle turtle = new Turtle(0,0,world);
//---------------------------------------------------------------//public void run(){
//Make the turtle invisibleturtle.hide();
//Prepare the penturtle.setPenColor(Color.RED);
turtle.setPenWidth(2);//Draw the axes in REDturtle.penUp();
turtle.moveTo(world.getWidth()/2,0);turtle.penDown();
turtle.moveTo(world.getWidth()/2,world.getHeight());turtle.penUp();
turtle.moveTo(world.getWidth(),world.getHeight()/2);turtle.penDown();
turtle.moveTo(0,world.getHeight()/2);turtle.penUp();
turtle.moveTo(0,0);//Prepare the variables
double xOff = 0.0;//offset relative to 1.0double yOff = -0.0;
double xScale = 1.0*world.getWidth()/2;double yScale = 0.9*world.getHeight()/2;
double yVal = 0;int row = 0;
int col = 0;double xVal = -1;
turtle.setPenColor(Color.BLUE);//Draw the cosine function in BLUE.
for(int cnt=0; cnt<=100;cnt++,xVal += 0.02){
//Get a y-value for the given x-value.yVal = function(xVal);
//Apply the offsets and scale the resultscol = (int)((xOff+xVal)*xScale);
row = (int)((yOff+yVal)*yScale);//Move to the first point without drawing a line because the// pen is not down. Translate the origin to the center in the
// process.turtle.moveTo(col + world.getWidth()/2,
row + world.getHeight()/2);//Lower the pen in order to draw a line from each point to the
// next point.turtle.penDown();
}//end for loop}//end run method//---------------------------------------------------------------////This method evaluates and returns the y-value for each x-value
// for a cosine function with no offset centered at the origin.// y = cos(2*pi*x)
double function(double xVal){double yVal = Math.cos(2*Math.PI*xVal);
return yVal;}//end function
//---------------------------------------------------------------//}//end class Cosine01Runner This section contains a variety of miscellaneous information.
Financial : Although the Connexionssite makes it possible for you to download a PDF file for this module at no charge, and also makes it possible for you topurchase a pre-printed version of the PDF file, you should be aware that some of the HTML elements in this module may not translate well intoPDF.
I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.
In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.
Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
-end-
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