Drawing scaling based on position in window size?

Processing Coding Questions
1

Hey guys so I want to know how a ball or drawing can be scaled as it moves from one area to the other? Say I have a ball and its being controlled by my mouse, at the bottom left corner its big, but as I move it towards the top right it gets small. How may I achieve this?

2

From the example here I did the following modification to change the size based on position along the Y axis.

Kf

final float MINSIZE=5;
final float MAXSIZE=60;
float rad = 60;        // Width of the shape
float xpos, ypos;    // Starting position of shape    

float xspeed = 2.8;  // Speed of the shape
float yspeed = 2.2;  // Speed of the shape

int xdirection = 1;  // Left or Right
int ydirection = 1;  // Top to Bottom


void setup() 
{
  size(640, 360);
  noStroke();
  frameRate(30);
  ellipseMode(RADIUS);
  // Set the starting position of the shape
  xpos = width/2;
  ypos = height/2;
  rad=calculateBallSize(ypos);
}

void draw() 
{
  background(102);
  
  // Update the position of the shape
  xpos = xpos + ( xspeed * xdirection );
  ypos = ypos + ( yspeed * ydirection );
  rad=calculateBallSize(ypos);
  
  // Test to see if the shape exceeds the boundaries of the screen
  // If it does, reverse its direction by multiplying by -1
  if (xpos > width-rad || xpos < rad) {
    xdirection *= -1;
  }
  if (ypos > height-rad || ypos < rad) {
    ydirection *= -1;
  }

  // Draw the shape
  ellipse(xpos, ypos, rad, rad);
}

float calculateBallSize(float ypos){
   return map(mouseY,0,height,MINSIZE,MAXSIZE);
}