is there a way to convert a float to an Int by rounding to nearest whole integer?
cheers
Sam
it works. But, how? shouldnt the int be 2.01? then how does the int go down?
Sam Jarman
2010-01-10 03:47:40
An integer is by definition a whole number, so how can it possibly have any fractional value?
Quick Joe Smith
2010-01-10 04:12:23
well if thats true, then shouldn't i = f ;just work?
Sam Jarman
2010-01-10 04:17:46
Doesn't work for negative numbers, see ergosys for correct answer.
BlueRaja - Danny Pflughoeft
2010-01-10 04:19:53
+3
A:
Actually Paul Beckingham's answer isn't quite correct. If you try a negative number like -1.51, you get -1 instead of -2.
The functions round(), roundf(), lround(), and lroundf() from math.h work for negative numbers too.
ergosys
2010-01-10 04:15:55
ah yes, I see. however, in my app negative numbers are not used. for next time, could you give me an example of those fuctions please?
Sam Jarman
2010-01-10 04:18:59
Rounding is one of those things you can get into arguments with others for hours. There's also a school of thought that says the "add a half and drop the fractional part" biases the outputs upward (because `k + 0` doesn't change and `k + 0.5` always goes up for a given integer `k`), so they recommend rounding even halves down and odd halves up (i.e. `k + 0.5` rounds to `k` for `k` = ..., -4, -2, 0, 2, 4, ... and it rounds to `k + 1` for `k` = ..., -3, -1, 1, 3, ...). Basically, the naive way can throw statistics off.
Mike DeSimone
2010-01-10 05:28:49