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Re: How best to implement a hash table in Mathematica

  • To: mathgroup at smc.vnet.net
  • Subject: [mg125061] Re: How best to implement a hash table in Mathematica
  • From: Joseph Gwinn <joegwinn at comcast.net>
  • Date: Mon, 20 Feb 2012 02:47:25 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <jho21j$5sb$1@smc.vnet.net> <jhqmsq$fbt$1@smc.vnet.net>

In article <jhqmsq$fbt$1 at smc.vnet.net>,
 Richard Fateman <fateman at cs.berkeley.edu> wrote:

> On 2/18/2012 3:28 AM, Joseph Gwinn wrote:
> > I have an application that resembles dictionary lookup, with significant
> > rates of collision.
> >
> >...
> 
> Mathematica presumably already uses hashing for storage of stuff like
> 
> f[{a,b,c}] = value1
> f[{1,2,c}] = value2
> 
> etc.
> 
> Initializing a hashtable with 10^4 (identical?) empty keys makes no
> sense. Did I misunderstand your message?

No, you understood correctly.  Please see my response to David Bailey 
for the rationale.

Joe Gwinn



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