OpenEuphoria

Re: floor()

• Posted by jluethje at gmx.de Apr 22, 2002
• 492 views

Hi,

Ricardo wrote:

> Well, not exactly adding 1, because if the argument is integer (after
> the division) you'll get a result off by 1.

Absolutely right. A good description can be found e.g. at
   http://mathworld.wolfram.com/FloorFunction.html

and related pages.

> These issues are treated in my package General Functions, where one
> can find FloorTowardsZero

This is called "fix" in many BASIC dialects and -- most intuitive for
me -- "trunc" e.g. in PASCAL or SPSS.

The principle of trunc(x) is:
   if x < 0 then
      return ceil(x)
   else
      return floor(x)
   end if

> Ceil, etc. routines. For example, Ceil(a) is -floor(-a).

Because those are standard functions (which are implemented in many
languages), I would appreciate it if
   ceil(x)
   trunc(x)
   frac(x)   -->  e.g. frac(-2.7) = -0.7
   abs(x)
   sign(x)

would be part of the official Euphoria release.


Regards,
   Juergen


-----------------
>> [...]
>> So be aware, when doing arithmetics on the results to add 1 to the
>> floor(-x/y) result.
>> [...]