package eanalysis;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
/**
* headline: Analysis
* Beschreibung:
* Copyright: Copyright (c) 2002
* Organisation: HAW
* @author Marc Heiligenstein
* @version 1.0
*/
public class Eanalysis extends Applet implements ActionListener{
// declaring the button
Button button1;
// the single-line text-components
TextField topTextField, startTextField,sumTextField;
// for displaying text
Label l,l2,steps, error,result;
// making some color for the font and the button
Color blue = new Color(25,0,240),red = new Color(150,0,50),green = new Color(0,100,100);
// the text windows for the result and the difference
TextArea tsteps, errort;
// for each result and difference
String s1 = "";
String s2 ="";
// to store the strings of each step
StringBuffer b1 = new StringBuffer(); //for the result
StringBuffer b2 = new StringBuffer(); //for the difference
/**initialise the applet, making the layout*/
public void init() {
// difining the layout
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints c = new GridBagConstraints();
setFont(new Font( "Helvetica" , Font.PLAIN, 12));
setLayout(gridbag);
// label basic number
c.weighty = 0.25; // giving some space vertically
c.weightx = 1.0; // giving some space horizontally
l = new Label( "Basic number : " );
gridbag.setConstraints(l, c);
add(l);
// text line basic
c.weighty =0.25; // giving some space vertically
c.gridwidth = GridBagConstraints.REMAINDER; // the last component in the row
topTextField = new TextField( "25" ,10); // initialising the text field with a value
topTextField.setFont(new Font( "Monospaced" ,Font.PLAIN,12));
gridbag.setConstraints(topTextField, c);
add(topTextField);
// lable start value addition
c.gridwidth = 1; // setting to the default value
l2 = new Label( "Startvalue of the addition and 1st divisor: " ); // the text of the label
gridbag.setConstraints(l2, c);
add(l2);
// text field for the start value of the addition
startTextField = new TextField( "7", 10 ); // initialising the text field with a value
startTextField.setFont(new Font( "Monospaced" ,Font.PLAIN,12));
c.gridwidth = GridBagConstraints.REMAINDER; // the last component in the row
gridbag.setConstraints(startTextField, c);
add(startTextField);
// setting the button
button1 = new Button( "GO" ); // initialising the button with the text
button1.setBackground(blue); // giving the color to the button
c.anchor = GridBagConstraints.CENTER; //setting the button to the center of its grid cell
gridbag.setConstraints(button1, c);
add(button1);
// when the button is pressed the method button1_actionPerformed(e) is called
button1.addActionListener(new java.awt.event.ActionListener(){
public void actionPerformed(ActionEvent e) {
button1_actionPerformed(e);
}
});
// lable result
c.gridwidth = 1; // setting to the default value
steps = new Label( "Result for every step : " );
gridbag.setConstraints(steps, c);
add(steps);
// lable difference
c.gridwidth = GridBagConstraints.REMAINDER; // the last component in the row
error = new Label( "Difference to the Java square root funktion : " );
gridbag.setConstraints(error, c);
add(error);
// text area for showing the result
c.gridwidth = 1; // setting to the default value
tsteps = new TextArea(s1,5,35,1);
tsteps.setEditable(false);
tsteps.setForeground(blue);
gridbag.setConstraints(tsteps, c);
add(tsteps);
// text area for showing the difference
c.gridwidth = GridBagConstraints.REMAINDER; // the last component in the row
errort = new TextArea(s2,5,35,1);
errort.setEditable(false);
errort.setForeground(red); // setting the color of the font
gridbag.setConstraints(errort, c);
add(errort);
// label square root
c.gridwidth = GridBagConstraints.REMAINDER; // the last component in the row
result = new Label( "Result of the Java square root function : " );
gridbag.setConstraints(result, c);
add(result);
// text field showing the result of the Java square root function
sumTextField = new TextField(20);
sumTextField.setEditable(false);
sumTextField.setForeground(green);
gridbag.setConstraints(sumTextField, c);
add(sumTextField);
}
// is needed because the actionPerformed()-method is an inner class
public void actionPerformed(ActionEvent l){}
// all this happens when the button is pressed
void button1_actionPerformed(ActionEvent e) {
double stat = Double.parseDouble(topTextField.getText()); //searching the square root from this number*
double temp = Double.parseDouble(startTextField.getText()); // Start value of the addition and divisor*
double wurzel = Math.sqrt(stat); //getting the square root from the Java square root funktion
if(stat >= 0 && temp > 0){ // the function only works if the basic number and the start value of the addition is greater or equal to 0
double bug = 0; // difference
double result = 999999998; // result
double previus = 999999999; //the previus result of the actual calculation
// the calculation happens as long as the previus result is greater than the actual result
for (int i=1; previus > result && result > 0.0; i++){
previus = result; //giving the actual result to the previus
result = (temp + stat / temp)/ 2; // calculating the result
temp = result; // the actual result is the start value of the addition for the next step
// if the previus result is greater then the actual result the actual result is written in the string
if(previus > result){
// counting the right way
if(i ==1){
s1 = new String( "\n" + i + "st step: " + Double.toString(result));}
else{
if(i == 2){
s1 = new String( "\n" + i + "nd step: " + Double.toString(result));}
else{
if(i == 3){
s1 = new String("\n" + i + "rd step: " + Double.toString(result));}
else{
s1 = new String("\n" + i + "th step: " + Double.toString(result));
}
}
}
// calculating the difference of the result of every step to the result of the Java square root function
if(wurzel > 0.0){ // only when the chosen number is positive and greater then 0
bug = result - wurzel; // calculating the difference for every step
s2 = new String( "\n\t" + Double.toString(bug));
}
// when choosing the 0 the result is the difference
else{
s2 = new String("\n\t" + "result = difference");
}
// storing the strings after every step
b1.append(s1);
b2.append(s2);
}
}
// after finishing the function the results are written in the text windows
tsteps.setText((b1.toString())); // result
errort.setText((b2.toString())); // difference
// showing the result of the square root function of Java
sumTextField.setText(" " + Double.toString(wurzel));
// delete for the next time
b1.delete(0,b1.length());
b2.delete(0,b2.length());
}
// this is showing when one of the chosen numbers is negative
else{
s1 = new String( "\n Only >= 0 for the basic number" );
tsteps.setText(s1);
s2 = new String( "\n Only > 0 \n for the startvalue and divisor" );
errort.setText(s2);
sumTextField.setText( " New numbers, please" );
}
}
}
