can anyone please check my method

[Bobby Marvikuan]

In my code there is a problem with a double number and I don't know how to solve that
Here is the method where the problem comes from:

public void paint(Graphics g) {
double factor = 1e6;
double widthPixel;
double heightPixel;
for (int x = 0; x < this.getWidth(); x++) {
for (int y = 0; y < this.getHeight(); y++) {
widthPixel = Math
.round((x / this.getWidth() * factor) / factor);
heightPixel = Math.round((y / this.getHeight() * factor)
/ factor);
double re = (-2 + widthPixel * 4);
double im = (1.6 - heightPixel * 3.2);
Complex c = new Complex(re, im);
// Complex temp = new Complex(x * widthPixel, y * heightPixel);
Complex temp = c;
for (int count = 0; count < 100; count++) {
// Complex temp = c;
c.square();
c.add(temp);
System.out.println(c.toString());
// c.toString();
if (c.modulusSquared() > 4) {
chooseColor(g, count);
// System.out.println(count);
g.drawLine(x, y, x, y);
break;
}
}
}
}
}

So, in here

widthPixel = Math
.round((x / this.getWidth() * factor) / factor);
heightPixel = Math.round((y / this.getHeight() * factor)
/ factor);

gives the value 0.0 whatever the values of x and y. Even if the value of y is 350 heightPixel =0.0. Can anyone help where the problem come from? =/ and second question how to make double to be value with 6 decimal places not only 2 as in this case? Cheers

[Anayonkar Shivalkar]

Hi Bobby Marvikuan,

Welcome to CodeRanch!

The reason is simple. You are doing some division operations before doing round operation.

Hint : a/b = 0 when a and b are int and a < b.

I hope this helps.

[Bobby Marvikuan]

 

Anayonkar Shivalkar wrote:Hi Bobby Marvikuan,

Welcome to CodeRanch!

The reason is simple. You are doing some division operations before doing round operation.

Hint : a/b = 0 when a and b are int and a < b.

I hope this helps.

Thank you so much! But shouldn't double be to 14 decimal points by default ? why it is only to 2? and OK it could be 0 between 0-699 but why when x=700 it is not 1 still 0?=/
Thanks for your answer by the way I get where I did have a mistake:)

[Anayonkar Shivalkar]

 

Bobby Marvikuan wrote:and OK it could be 0 between 0-699 but why when x=700 it is not 1 still 0?

Well, as per your for loop, x will always be less than width and y will always be less than height So, if width is 700, maximum value of x would be 699 and 699/700 is 0 in int format

And about decimal points, well, if you are doing operations with double numbers, then yes, rounding off makes sense. But you are already doing operations with int (so, 1/2 would be 0, not 0.5).

I hope this helps.

[dennis deems]

To put it more succinctly, the result of int/int is an int.

[Bobby Marvikuan]

 

Dennis Deems wrote:To put it more succinctly, the result of int/int is an int.

cheers

[Bobby Marvikuan]

 

Anayonkar Shivalkar wrote:

Bobby Marvikuan wrote:and OK it could be 0 between 0-699 but why when x=700 it is not 1 still 0?

Well, as per your for loop, x will always be less than width and y will always be less than height So, if width is 700, maximum value of x would be 699 and 699/700 is 0 in int format

And about decimal points, well, if you are doing operations with double numbers, then yes, rounding off makes sense. But you are already doing operations with int (so, 1/2 would be 0, not 0.5).

I hope this helps.

thank you!