1. Member Join Date
Dec 2011
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## Math issue

I'm having an issue with a small java program that I have written :
Java Code:
```int coords[]={500, 750};
int vline[]={1, 1};

double a = coords + coords;
double b = vline + vline;
double c = a / b;
double d = c - coords;
double d1 = c - coords;
double e = c - d1;
double e1 = c - d;

System.out.println(e);
System.out.println(e1);```
The two arrays at the top with the current values print out the following result e = 750.0, e1 = 500.0. However if I change the values in the vline array to for example "int vline[]={2, 1};" I should get the results e = 333.3333333333333, e1 = 83.33333333333331, but I don't I get the results e = 750.0, e1 = 500.0.  Reply With Quote

2. ## Re: Math issue

What is the difference between integer and floating point division?  Reply With Quote

3. Member Join Date
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## Re: Math issue Originally Posted by Junky What is the difference between integer and floating point division?
I have no idea, what is the difference?  Reply With Quote

4. ## Re: Math issue

Java Code:
```System.out.println(2 / 3);
System.out.println(2.0 / 3);```
Run that code and see what results you get.  Reply With Quote

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## Re: Math issue

I get 0 for the first line and 0.6666666666666666 for the second, so what am I doing wrong?  Reply With Quote

6. ## Re: Math issue

Isn't it obvious? The first line is doing integer division. Since integers do not have a floating point part whatever comes after the decimal point gets truncated.  Reply With Quote

7. Member Join Date
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## Re: Math issue

So I have changed coords and vline to doubles and I'm still having the same problem was that what I needed to change or some thing completely different?  Reply With Quote

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## Re: Math issue

Try printing each of the values as you calculate them to see at which point your program is not doing what you expect or intend.

If you can't understand the resulting output, post runnable code.  Reply With Quote

9. Member Join Date
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## Re: Math issue

I have done so and this is what I'm getting if the values for coord are 500, 750 and the values for vline are 2, 1:
a = 1250.0
b = 3.0
c = 416.6666666666667
d = -83.33333333333331
d1 = -333.3333333333333
e = 750.0
e1 = 500.0  Reply With Quote

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## Re: Math issue  Reply With Quote

11. Member Join Date
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## Re: Math issue

Why do you feel like your results are wrong? Do the math on a calculator, you'll get the same thing.  Reply With Quote

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