numbers

[Zas]

How can I round numbers down, and how can I round them up.
I.E. How can I get:
2 = 3 / 2;
# OR
1 = 3 / 2;
Thanks, Happieness is like peeing your pants.
Everyone can see it, but only you can feel the warmth.

 

[mikevh]

To round down, you can use the int() function,
which will discard the fractional part of the
result:

print int(3 /2) #prints "1"

To round them up, add 0.5 after the division and
before you apply th int() function:

print int(3 / 2 + 0.5) #prints "2"

 

[Zas]

errr.. oh i see for rounding up, only it would be + 1, because 3.1 rounded all the way up is 4.

hrm.
$ttr = int( 3 / 2 );
# $trr is than 1? ok. thanks Happieness is like peeing your pants.
Everyone can see it, but only you can feel the warmth.

 

[obscurifer]

You can also use the ceil() and floor() functions in the POSIX module.

Example:
=========
use POSIX;

print floor(3/2) . "\n" . ceil(3/2) . "\n";
=========

This doesn't exactly round the number, but it does return the floor and ceiling.

 

[Wonboodoo]

The POSIX solution is better because the "int" solution will produce problems for divisions where there is no fraction. Suppose your division is 4/2. Both the round-down and round-up should be 2 whereas the "int" solution you've listed here will probably return 3 for the round-up.

 

[icrf]

add 0.5 and truncate is the just the world's fastest simple rounding, it's not always a round up. For instance:

1.2 + 0.5 = 1.7 truncated/rounded: 1
1.8 + 0.5 = 2.3 truncated/rounded: 2
1.5 + 0.5 = 2.0 truncated/rounded: 2

I don't know about any speed issues with the POSIX module, but the solutions sound simple enough a manual implementation might be best. I'm sure rounding down would be fastest just truncating. Rounding up might be best as truncating and adding one. ----------------------------------------------------------------------------------
...but I'm just a C man trying to see the light