Making Random Numbers

Your program can generate a random number in a specified range.

void random(float max) 

• Returns a random float between 0 and max

float xPos = random(width);   // Sets xPos to a random number from 0 to width

void random(float min,  float max )

• Returns a random float between min and max

float xPos = random(200, 500);   // Sets xPos to a random number from 200 to 500

It's important to note that random generates a value that includes minimum but excludes maximum.  For example, random(50, 200) actually generates a number between 50 and 199.999999999.   This will be important later!

An Example

Let's  look at some example code in action.  Copy the code below into a new processing project.  Run the program to see it in action.   Try changing some values and see what happens!   How might you get different colors to appear?

float redAmount;

float xPos;

float yPos;

void setup()

{

   fullScreen();          

}

void draw()

{

   xPos = random(50, width - 50);

   yPos = random(400, height - 400);

   redAmount = random(255);

   fill(redAmount, 0, 0); 

   ellipse(xPos, yPos, 50, 50);   

}