Services & ResourcesWolfram ForumsMathGroup Archive

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

Re: why no result & no error from this recursion

• To: mathgroup at smc.vnet.net
• Subject: [mg82431] Re: [mg82403] why no result & no error from this recursion
• From: Sseziwa Mukasa <mukasa at jeol.com>
• Date: Sat, 20 Oct 2007 05:49:12 -0400 (EDT)
• References: <200710190904.FAA05304@smc.vnet.net>

On Oct 19, 2007, at 5:04 AM, Murray Eisenberg wrote:

> Why does the following recursion produce neither a result nor an error
> message -- nor a system crash?
>
> Block[{$RecursionLimit=50002}, (If[#<1, "", "." <> #0[# - 1]] &) 
> [50000]]
>
> I even tried setting $RecursionLimit=Infinity, but no change.
>
> I presume this is just bumping up against a hardware/OS limit, so I'm
> surprised to get no error message and no crash.

My guess is that the front end is having problems formatting 50000  
'.' for display.  I've noticed sometimes that calculations that  
generate long strings on output can appear to have hung but the  
kernel has not crashed and the front end is unresponsive.

Regards,

Ssezi

• Follow-Ups:
  • Re: Re: why no result & no error from this recursion
    • From: Murray Eisenberg <murray@math.umass.edu>

• References:
  • why no result & no error from this recursion
    • From: Murray Eisenberg <murray@math.umass.edu>