# All Questions

**1971**

votes

**22**answers

197389 views

### Is floating point math broken?

0.1 + 0.2 == 0.3
-> false
0.1 + 0.2
-> 0.30000000000000004
Why does this happen?

**189**

votes

**3**answers

23406 views

### Why are these numbers not equal?

The following code is obviously wrong. What's the problem?
i <- 0.1
i <- i + 0.05
i
## [1] 0.15
if(i==0.15) cat("i equals 0.15") else cat("i does not equal 0.15")
## i does not equal 0.15

**384**

votes

**34**answers

230095 views

### How to deal with floating point number precision in JavaScript?

I have the following dummy test script:
function test(){
var x = 0.1 * 0.2;
document.write(x);
}
test();
This will print the result 0.020000000000000004 while it should just print 0.02 (if ...

**704**

votes

**14**answers

198337 views

### Why not use Double or Float to represent currency?

I've always been told never to represent money with double or float types, and this time I pose the question to you: why?
I'm sure there is a very good reason, I simply do not know what it is.

**127**

votes

**3**answers

11987 views

### Why Are Floating Point Numbers Inaccurate?

Why do some numbers lose accuracy when stored as floating point numbers?
For example, the decimal number 9.2 can be expressed exactly as a ratio of two decimal integers (92/10), both of which can be ...

**29**

votes

**7**answers

76110 views

### Floating point inaccuracy examples

How do you explain floating point inaccuracy to fresh programmers and laymen who still think computers are infinitely wise and accurate?
Do you have a favourite example or anecdote which seems to get ...

**52**

votes

**6**answers

20054 views

### Why is 24.0000 not equal to 24.0000 in MATLAB?

I am writing a program where I need to delete duplicate points stored in a matrix. The problem is that when it comes to check whether those points are in the matrix, MATLAB can't recognize them in the...

**409**

votes

**25**answers

284054 views

### What is the most effective way for float and double comparison?

What would be the most efficient way to compare two double or two float values?
Simply doing this is not correct:
bool CompareDoubles1 (double A, double B)
{
return A == B;
}
But something like...

**70**

votes

**7**answers

127903 views

### Division of integers in Java

This is a basic question but I can't find an answer. I've looked into floating point arithmetic and a few other topics but nothing has seemed to address this. I'm sure I just have the wrong terminol...

**582**

votes

**13**answers

479407 views

### How can I force division to be floating point? Division keeps rounding down to 0

I have two integer values a and b, but I need their ratio in floating point. I know that a<b and I want to calculate a/b, so if I use integer division I'll always get 0 with a remainder of a.
How...