Thanks for your response!
I haven't been taught about the Timer class.
I am using the CircleFigure class, which has the following methods: moveRight(x),moveLeft(x),moveUp(x),moveDown(x),moveTo(x,y),setRadius(x),
setColour(c),drawHollow(),drawFilled(),getXCentre() and getYCentre().
Ultimately, I cannot use the Timer class for this problem.
Here is my code, which makes the circle move around a perimeter of 400 pixels. I know that I have to use the random method from the Math class to generate a number between 0 and 1, which will decide on the direction.
Note that this is missing from the code:
[code]
public class MovingCircle3 {
public static void main (
String [ ] args) {
/*Create a circle of radius 30 pixels at position(30,30).
Circle is to move at a rate of 5 pixels every 20 milliseconds to follow the perimeter of the square (400 pixels).
Initially the circle is to move in a clockwise direction.
However at each move the circle must have a probability of 0.01 to change direction.
*/
[code]
public class MovingCircle1{
public static void main ( String [ ] args){
CircleFigure.create();
CircleFigure.setRadius(30);
CircleFigure.moveTo(30,30);
int x = CircleFigure.getXCentre();
int y = CircleFigure.getYCentre();
double randomNum;
double probDirectionChange = 0.01;
while (true) {
do {
Delay.milliseconds(20);
x = x + 5;
CircleFigure.moveRight(5);
}
while ( x != 430);
do {
Delay.milliseconds(20);
y = y + 5;
CircleFigure.moveDown(5);
}
while ( y != 430);
do {
Delay.milliseconds(20);
x = x - 5;
CircleFigure.moveLeft(5);
}
while ( x != 30);
do {
Delay.milliseconds(20);
y = y - 5;
CircleFigure.moveUp(5);
}
while ( y != 30);
}
}
}
I have also written other slight variations of the code above. I also tried placing if-statements within each of the do-loops. The circle however just changes its direction for a second and immediately continues on its clockwise path. The correct way is that when the circle changes its direction with prob. 0.01 and thus starts moving anti-clockwise, then the probability of changing back to clockwise is 0.01 and vice versa. At the start the probability of changing the direction from clockwise to anti-clockwise is 0.01 and this is a constant.
However the random number (Math.random()) needs to be generated each time, the circle moves 5 pixels, so there is always a chance of direction change.
So far i've just been unable to utilize the Math.class correctly for this purpose, or is there something else I overlooked?
A thousand thanks for any assistance!
