Develop Reference

Which parameter has the most impact on result in apache OLSMultipleLinearRegression

I'm experimenting with OLSMultipleLinearRegression and I wonder which of my parameters has most impact on the prediction. I do not understand which method in OLSMultipleLinearRegression that will return that information.
static void test() {
double y[] = {110, 120, 135, 140};
double data[][] = {
{9, 100},
{21, 260},
{29, 490},
{41, 650}
};
OLSMultipleLinearRegression regression = new OLSMultipleLinearRegression();
regression.newSampleData(y, data);
double[] beta = regression.estimateRegressionParameters();
for(int i = 0;i<beta.length;i++) {
System.out.printf("b%d = %.3f\n",i, beta[i]);
}
int ROW = 3;
double value = y[ROW];
double predict = beta[0] + beta[1] * data[ROW][0] + beta[2] * data[ROW][1];
System.out.printf("y=%.3f + %.3f * %.3f + %.3f * %.3f\n", beta[0],beta[1],data[ROW][0],beta[2],data[ROW][1]);
System.out.printf("predict=%.3f value=%.3f\n", predict, value );
}

how to calculate shoutPower for my libGdx game?

this.maxHp = 100;
this.hp = this.maxHp;
it's mean objeact got 100hp and if we hit object, it's subtracted 5 hp from object.
here is method th check if object take damage:
public boolean takeDamage(int dmg) {
hp -= dmg;
reddish += 1.0f;
if (hp <= 0) {
return true;
}
return false;
}
here is method to check if bullet hit object:
public void checkCollisions() {
List<Bullet> b = bulletEmitter.getActiveList();
for (int i = 0; i < b.size(); i++) {
for (int j = 0; j < players.size(); j++) {
if (b.get(i).isArmed() && players.get(j).getHitArea().contains(b.get(i).getPosition())) {
b.get(i).deactivate();
players.get(j).takeDamage(5);
map.clearGround(b.get(i).getPosition().x, b.get(i).getPosition().y, 8);
continue;
}
}
I need to show taking damage (int dmg), damage might be any variable which we put in method takeDamage(int dmg). int this case int dmg = 5;
I can't calculate it this:
result = maxHp - hp
increase result on 5hp with evry hit
5.. 10.. 15.. 20..
here is method, which i put font in:
damageFont.draw(batch, "" + (maxHp - hp), position.x, position.y + 130, 85, 1, false);
}
}
(maxHp - hp) - increase result on 5hp with evry hit 5.. 10.. 15.. 20..
instead this, i need to calculate ammount of deal damage, but not with constant values.
(maxHp - hp) something instead this just should return 5, if we put 5 in takeDamage(int dmg)
or 10, if we put 10.
it's amount of damage take with evry hit:
should be 5, 5, 5, 5
not: 5... 10... 15... 20

Just like MarsAtomic mentioned you allready have your damage per hit, just save it as a new instance variable and display it instead of (maxHp - hp):
private int damageTaken;
public boolean takeDamage(int dmg) {
damageTaken = dmg;
hp -= dmg;
reddish += 1.0f;
if (hp <= 0) {
return true;
}
return false;
}
and when you draw your font:
damageFont.draw(batch, "" + damageTaken, position.x, position.y + 130, 85, 1, false);

how to use millis() to display images every x seconds?

I have an array of candy images which are randomly chosen. There are candies falling and I want to make a new one fall every 5 seconds, and I know I have to use millis() - but how would I implement it into my program? I tried using millis() like so:
int time = millis();
if (time<5*1000)
{
image(goodCandy[rand], randX, goodY, randCandyW, randCandyH);
goodY = goodY + (candySpeed * yDirCandy);
time = millis();
}
But it only appears for 5 seconds then goes away.
I also tried:
int time = millis();
if (millis() - time >= 5000)
{
image(goodCandy[rand], randX, goodY, randCandyW, randCandyH);
goodY = goodY + (candySpeed * yDirCandy);
time = millis();
}
But it didn't work.
Here's the simplified code:
PImage [] goodCandy = new PImage [3];
int candySpeed = 20;
int yDirCandy = 1;
int candyY = 10;
int candyX = 200;
int candyW = 187;
int candyH = 121;
int randCandyW = 100;
int randCandyH = 100;
int goodY = -200;
int rand=(int) (2*Math.random()) +1;
int randX = (int) (1500*Math.random())+20;
void setup() {
for (int i=0; i<goodCandy.length; i++) {
goodCandy[i] = loadImage("goodCandy" + i + ".png");
}
void draw() {
if (current=="play") {
loadStuff();
}
}
void loadStuff() {
image(candy, candyX, candyY, candyW, candyH); //original candy
candyY = candyY + (candySpeed * yDirCandy);
int time = millis();
if (millis() - time >= 5000)
{
image(goodCandy[rand], randX, goodY, randCandyW, randCandyH);
goodY = goodY + (candySpeed * yDirCandy);
time = millis();
}
//for (int i=0; i<time; i++) {
// image(goodCandy[rand], randX, goodY, randCandyW, randCandyH);
// goodY = goodY + (candySpeed * yDirCandy);
// time = millis();
//}
}
Any ideas how I could make millis() work so I can have a random candy falling every 5 seconds?
Thanks

Please try to get into the habit of breaking your problem down into smaller pieces and only taking on those pieces one at a time. For example, you should probably start with a simpler sketch that just shows a random circle every 5 seconds.
Here's a small example that shows how you would use the millis() function to draw something every 5 seconds:
int lastCircleTime = 0;
void draw() {
if (millis() > lastCircleTime + 5*1000) {
ellipse(random(width), random(height), 20, 20);
lastCircleTime = millis();
}
}
If you're still having trouble, please post a MCVE showing exactly which step you're stuck on. Note that this should not be your whole sketch. It should be a small example like this one. Good luck.

Java Countdown Timer

Hi I am trying to create a countdown stopwatch timer for my gym.
Here is what I have for the actual displaying and decrementing of the time: (bear in mind I used my normal stopwatch one and just edited it briefly to decrement. It is still first pass and I still want to thread it all at some stage but for now this should work. )
new Timer(1,new ActionListener(){
public void actionPerformed(ActionEvent e){
int seconds = (int)(System.currentTimeMillis()-watchStart)/1000;
int days = seconds / 86400;
//these are just initialization values for testing
int startHour, startMin, startSec;
startHour = 5;
startMin = 5;
startSec = 0;
int hours = (seconds / 3600) - (days * 24);
int min = (seconds / 60) - (days * 1440) - (hours * 60);
int sec = seconds % 60;
String s = String.format("%02d:%02d:%02d", startHour - hours, startMin - min, ((startSec == 0) ? startSec = 60 : startSec) - sec );
displayTimeLabel.setText(s);
}
});
Now my issue is:
a) It is not decrementing the minute to start with (if it starts at say 5 minutes)
b) If I start it at 30 seconds it will go into negative until it reaches a full minute then decrements the minute. ( I think I will need a method like if == 0 then minute - 1? but I fear that will break the actual count?)
Thanks.
Edit: Full program:
package countdown;
import java.awt.*;
import static java.awt.Frame.MAXIMIZED_BOTH;
import javax.swing.Timer;
import javax.swing.*;
import java.awt.event.*;
public class CountDown extends JFrame implements ActionListener{
private int hour;
private int minute;
private int second;
// The component that shows the elapsed time.
private JLabel displayTimeLabel;
private long watchStart, watchEnd;
private Timer theChronometer;
// Keeps track of time when pausing the Timer.
private long pausedTime;
// Lets the program know if starting or resuming
private boolean paused = false;
// Button that changes from "Start" to "Resume" depending on pause status.
private JButton activateTimerButton;
// run the program
public static void main(String[] args) {
CountDown count = new CountDown();
count.setVisible(true);
count.setLocationRelativeTo(null);
}
public CountDown(){
// initialize
super();
setExtendedState(MAXIMIZED_BOTH);
setLayout(new BorderLayout());
setLayout(new GridLayout(2,1));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("CrossFit Slam");
setBackground(Color.black);
setForeground(Color.white);
Font largeFontBOLD = new Font("Calibri", Font.BOLD,20);
Font largeFontPLAIN = new Font("Calibri", Font.PLAIN,200);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new FlowLayout());
activateTimerButton = new JButton("Start");// will display resume when the watch is paused
JButton stopTimerButton = new JButton("Stop");
JButton pauseTimerButton = new JButton("Pause");
// register buttons to generate events when clicked
activateTimerButton.addActionListener(this);
stopTimerButton.addActionListener(this);
pauseTimerButton.addActionListener(this);
// the display for elapsed time
displayTimeLabel = new JLabel("00:00:00");
displayTimeLabel.setHorizontalAlignment(JLabel.CENTER);
buttonPanel.setBackground(Color.black);
buttonPanel.setForeground(Color.white);
displayTimeLabel.setFont(largeFontPLAIN);
displayTimeLabel.setForeground(Color.white);
displayTimeLabel.setBackground(Color.black);
activateTimerButton.setFont(largeFontBOLD);
stopTimerButton.setFont(largeFontBOLD);
pauseTimerButton.setFont(largeFontBOLD);
displayTimeLabel.setOpaque(true);
buttonPanel.add(activateTimerButton);
buttonPanel.add(stopTimerButton);
buttonPanel.add(pauseTimerButton);
add(displayTimeLabel);
add(buttonPanel, BorderLayout.PAGE_END);
theChronometer =
new Timer(1,new ActionListener(){
public void actionPerformed(ActionEvent e){
int seconds = (int)(System.currentTimeMillis()-watchStart)/1000;
int days = seconds / 86400;
int startHour, startMin, startSec;
startHour = 5;
startMin = 5;
startSec = 0;
int hours = (seconds / 3600) - (days * 24);
int min = (seconds / 60) - (days * 1440) - (hours * 60);
int sec = seconds % 60;
String s = String.format("%02d:%02d:%02d", startHour - hours, startMin - min, ((startSec == 0) ? startSec = 60 : startSec) - sec );
displayTimeLabel.setText(s);
}
});
}
public void actionPerformed(ActionEvent e){
if(e.getActionCommand().equals("Stop")){theChronometer.stop();}
else if(e.getActionCommand().equals("Start") || e.getActionCommand().equals("Resume")){
if(!paused){
watchStart = System.currentTimeMillis();
theChronometer.start();
}
else{
watchStart = System.currentTimeMillis()+pausedTime;
pausedTime = 0;
theChronometer.start();
paused = false;
activateTimerButton.setText("Start");
}
}
else if(e.getActionCommand().equals("Pause")){
long now = System.currentTimeMillis();
pausedTime -= (now - watchStart);
theChronometer.stop();
paused = true;
activateTimerButton.setText("Resume");
}
}
}

What you're trying to is easily achieved using standard libraries, in particular the Date class.
DateFormat f = new SimpleDateFormat("HH:mm:ss");
f.setTimeZone(TimeZone.getTimeZone("GMT"));
long startingTime = TimeUnit.HOURS.toMillis(5) + TimeUnit.MINUTES.toMillis(5);
public void actionPerformed(ActionEvent e) {
long elapsed = System.currentTimeMillis() - startTimestamp;
long displayTs = startingTime - elapsed;
String out;
if (displayTs >= 0) {
out = f.format(new Date(displayTs));
} else {
out = "-" + f.format(new Date(-displayTs));
}
displayTimeLabel.setText(out);
}
All of this is in the standard Java libraries and the Javadoc on the methods/classes should provide insight on what's happening.

I can't get the calculations to work

I have a calculator that is suposed to figure the volume and the results come back as "0"
JButton btnCalculateVlmn = new JButton("Calculate Hot Tub Volume");
btnCalculateVlmn.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent arg0)
{
double width = 0, length = 0, depth = 0, volume = 0;
String lengthString, widthString, depthString;
lengthString = hotTubLengthText.getText();
widthString = hotTubWidthText.getText();
depthString = hotTubDepthText.getText();
try
{
if (rdbtnRoundTub.isSelected())
{
volume = Math.PI * Math.pow(length / 2.0, 2) * depth;
}
else
{
volume = Math.PI * Math.pow(length * width, 2)
* depth;
}
DecimalFormat formatter = new DecimalFormat("#,###,###.###");
hotTubVolumeText.setText("" + formatter.format(volume));
}
catch (NumberFormatException e)
{
labelTubStatus
.setText("Fill in all fields");
}
}
});
btnCalculateVlmn.setBounds(20, 200, 180, 20);
hotTubs.add(btnCalculateVlmn);
JButton Exit = new JButton("Exit");
Exit.setBounds(220, 200, 80, 20);
Exit.addActionListener(this);
hotTubs.add(Exit);
}

depth is declared as 0 and never overwritten... so the volume is always 0.
I guess you should do something like:
...
double width = 0, length = 0, depth = 0, volume = 0;
String lengthString, widthString, depthString;
lengthString = hotTubLengthText.getText();
widthString = hotTubWidthText.getText();
depthString = hotTubDepthText.getText();
depth = Double.valueOf(depthString);
length = Double.valueOf(lengthString);
width = Double.valueOf(widthString);
....

You forgot to convert the strings (lengthString, widthString and depthString) to doubles and assign them to your variables (length, width and depth).

you have depth = 0 and
anything * 0 = 0

you forgot to convert your strings from the input fields to double.
you get 0 as result because you set length and width to 0

In both branches of your main if condition your expressions ending * depth. However this depth variable seems to be set to 0 and not set to anything else. So volume will always be 0 since whatever you multiply by 0 will be 0.
Maybe you've wanted to use depthString. Something like this:
depth = Integer.parseInt(depthString);
if (rdbtnRoundTub.isSelected())
{
volume = Math.PI * Math.pow(length / 2.0, 2) * depth;
}
else
{
volume = Math.PI * Math.pow(length * width, 2) * depth;
}