# Cant find solution for restart

**URL:** <https://discourse.processing.org/t/cant-find-solution-for-restart/15462>\
**Category:** Coding Questions\
**Tags:** homework\
**Created:** [November 13, 2019, 4:41pm UTC](https://discourse.processing.org/t/cant-find-solution-for-restart/15462 "2019-11-13T16:41:14Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![actuallyagod](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@actuallyagod](https://discourse.processing.org/u/actuallyagod)\
**Post date:** [November 13, 2019, 4:41pm UTC](https://discourse.processing.org/t/cant-find-solution-for-restart/15462/1 "2019-11-13T16:41:14Z")

</div>

Hi All!

I have been trying to add a restart button to this code but variables dont seem to work for me or maybe im doing it wrong. As of now i have tried to add:

```auto
void keyPressed() {
 if(key == 'r') {
  restart();
 }
}

void restart() {
 And then some of my variables
}

```

However i cannot figure it out, anyways here is my code

```auto
PImage img;
ArrayList<PVector> data;

float m = 1;
float b = 0;

void setup() {
  img = loadImage("Cykelsti.jpg");
  size(600, 600);
  data = new ArrayList<PVector>();
}

void LinearRegression() {
  float xsum = 0;
  float ysum = 0;

  for (int i = 0; i < data.size(); i++) {
    PVector point = data.get(i);
    xsum += point.x;
    ysum += point.y;
  }

  float xmean = xsum / data.size();
  float ymean = ysum / data.size();

  float num = 0;
  float den = 0;
  for (int n = 0; n < data.size(); n++) {
    PVector point = data.get(n);
    float x = point.x;
    float y = point.y;
    num += (x - xmean) * (y - ymean);
    den += (x - xmean) * (x - xmean);
  }

  m = num/den;
  b = ymean - m * xmean;
}
void drawLine () {
  float x1 = 0;
  float y1 = m * x1 + b;

  float x2 = width;
  float y2 = m * x2 + b;

  stroke(255, 0, 255);
  line(x1, y1, x2, y2);
}

void mousePressed () {
  PVector point = new PVector(mouseX, mouseY);
  data.add(point);
}

void draw() {
  background(51);
  image(img, 0, 0, width, height);
  for (int i = 0; i < data.size(); i++) {
    PVector point = data.get(i);
    fill(255, 0, 0);
    stroke(255);
    ellipse(point.x, point.y, 8, 8);
  }
  if (data.size() > 1) {
    LinearRegression();
    drawLine();
  }
}

```

Thanks for reading

---

<div class="post-metadata">

**Author:** ![paulgoux](https://avatars.discourse-cdn.com/v4/letter/p/b9bd4f/32.png) [@paulgoux](https://discourse.processing.org/u/paulgoux)\
**Post date:** [November 13, 2019, 7:51pm UTC](https://discourse.processing.org/t/cant-find-solution-for-restart/15462/2 "2019-11-13T19:51:19Z")

</div>

> [@actuallyagod](#):
>
> ```auto
> void keyPressed() {
> if(key == 'r') {
> restart();
> }
> }
> 
> void restart() {
> And then some of my variables
> }
> 
> ```
> 
> However i cannot figure it out, anyways here is my code
> 
> ```auto
> PImage img;
> ArrayList<PVector> data;
> 
> float m = 1;
> float b = 0;
> 
> void setup() {
> img = loadImage("Cykelsti.jpg");
> size(600, 600);
> data = new ArrayList<PVector>();
> }
> 
> void LinearRegression() {
> float xsum = 0;
> float ysum = 0;
> 
> for (int i = 0; i < data.size(); i++) {
> PVector point = data.get(i);
> xsum += point.x;
> ysum += point.y;
> }
> 
> float xmean = xsum / data.size();
> float ymean = ysum / data.size();
> 
> float num = 0;
> float den = 0;
> for (int n = 0; n < data.size(); n++) {
> PVector point = data.get(n);
> float x = point.x;
> float y = point.y;
> num += (x - xmean) * (y - ymean);
> den += (x - xmean) * (x - xmean);
> }
> 
> m = num/den;
> b = ymean - m * xmean;
> }
> void drawLine () {
> float x1 = 0;
> float y1 = m * x1 + b;
> 
> float x2 = width;
> float y2 = m * x2 + b;
> 
> stroke(255, 0, 255);
> line(x1, y1, x2, y2);
> }
> 
> void mousePressed () {
> PVector point = new PVector(mouseX, mouseY);
> data.add(point);
> }
> 
> void draw() {
> background(51);
> image(img, 0, 0, width, height);
> for (int i = 0; i < data.size(); i++) {
> PVector point = data.get(i);
> fill(255, 0, 0);
> stroke(255);
> ellipse(point.x, point.y, 8, 8);
> }
> if (data.size() > 1) {
> LinearRegression();
> drawLine();
> }
> }
> 
> ```

here’s my go to button class, you can make your own as I’ve done here but there are plenty of great libraries with much better functionality.

```auto
class Button{
  
  float x,y,w,h;
  int toggle = 0;
  String label;
  boolean pressed = false;
  Button(float xx, float yy, float ww, float hh, String Label){
    
    x = xx;
    y = yy;
    w = ww;
    h = hh;
    label = Label;
  }
  void draw(){
    noStroke();
    fill(255);
    rect(x,y,w,h);
    fill(0);
    text(label,x+5,y+h-5);
  }
  
  boolean pos(){
    
    return x < mouseX && mouseY < x + w && y< mouseY && mouseY < y + h;
  }
  
  void click(){
    if(pos()){
      toggle ++;
    }
    
    if(toggle==2){
      toggle = 0;
    }
  }
};

```

then create a new button variable.

```auto
Button reset

```

```auto
void Reset(){
  if (reset.toggle==1){
    //values you want to reinitialize
  }
}

```

```auto
void mousePressed(){
  if(mouseButton == LEFT && ! reset.pos() && ! trim.pos()){
  toggle++;
  if(toggle == 2){
    toggle = 0;
  }}
  
  if(mouseButton == RIGHT && ! reset.pos() && ! trim.pos()){
    
    inc = -inc;
  }
  if(mouseButton == LEFT && reset.pos()){
  reset.click();
  }
  
  if(mouseButton == LEFT && trim.pos()){
  trim.click();
  }
  
};

```

```auto
include a global "toggle variable"
int toggle = 0;

```

then in setup

```auto
void setup(){
  reset = new Button(1140,10,50,20, "reset");

```

then in draw

```auto

reset.draw();

```