http://qs1969.pair.com?node_id=300157

This is a comment on the FAQ Does perl have a round function? What about ceil() and floor()? Trig functions?. See also vroom's How do I round a floating point number?

An effective way to "ceil" if you don't have a perl version capable of "ceil" (such as a specialized small Windows distro), you can effectively "ceil" this way: $ceiled_number = int( $float + 0.99999999 );

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Re: ceil without ceil
by why_bird (Pilgrim) on Mar 13, 2008 at 14:48 UTC
    I think this would be better: 
    sub RoundUp
{
$float=$_[0];
...
..check that your input is valid here..
...
my $rounded_number=$float;
  if($float==int($float)){
  }elsif($float>0){
     $rounded_number=int($float+1);
###################################
## and optionally, depending how ##
## you want to define ceil() on  ##
## a number less than 0..        ##
  }elsif($float<0){
     $rounded_number=int($float-1); 
  }
###################################

return rounded_number;
}

    [download]
    The code above rounds any number smaller than 9e-9 incorrectly to 0. For a lot of applications I suppose this won't make a difference, but why write a mathematical function that is not correct? It might be copied by someone else who assumes that it will work correctly in every circumstance*.
    *Yes it would be a stupid assumption to make, but you can never tell..
    waits for someone to point out the error in her method
    why_bird
    ........
    Those are my principles. If you don't like them I have others.
    -- Groucho Marx
    .......
[reply]
[d/l]

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