Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Limit of Floor function

  • To: mathgroup at smc.vnet.net
  • Subject: [mg73852] Re: Limit of Floor function
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Fri, 2 Mar 2007 06:26:40 -0500 (EST)
  • Organization: The Open University, Milton Keynes, UK
  • References: <es6dgu$s4l$1@smc.vnet.net>

Eric Smith wrote:
> Mathematica 5.2 evaluates one-sided limits of the Floor function
> correctly.  But if I just ask:
> 
>    Limit[Floor[x],x->10]
> 
> It replies "10".  Shouldn't it tell me the limit is undefined,
> since the Floor function has a step discontinuity at every integer
> value?
> 
> Thanks,
> Eric
> 

Limit does not check both sides of the required value. You should 
manually check the limit on the left and on the right.

In[1]:=
Limit[Floor[x], x -> 10]

Out[1]=
10

(* Limit on the right *)

In[2]:=
Limit[Floor[x], x -> 10, Direction -> -1]

Out[2]=
10

(* Limit on the left *)

In[3]:=
Limit[Floor[x], x -> 10, Direction -> 1]

Out[3]=
9

Regards,
Jean-Marc


  • Prev by Date: Regression
  • Next by Date: Re: change filename automatically in Export Command
  • Previous by thread: Re: Limit of Floor function
  • Next by thread: Re: Limit of Floor function