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DeleteDuplicates is too slow?

• To: mathgroup at smc.vnet.net
• Subject: [mg107150] DeleteDuplicates is too slow?
• From: "Zeringue, Clint M Civ USAF AFMC AFRL/RDLAF" <Clint.Zeringue at kirtland.af.mil>
• Date: Thu, 4 Feb 2010 06:26:02 -0500 (EST)

Hello,

Suppose you have the following.

Data = RandomReal[1,{N,2}];

sameQ[_,_]=False;
sameQ[{x_,y_},{x_,z_}]=True;

Timing[DeleteDuplicates[data,sameQ]][[1]];

If N is a large number this takes an ungodly amount of time?

Is there a more efficient way to delete the duplicate entries of Data ?

ie.

Data = {{1.,2.},{1.,3.},{2.,3.}};

Would become:
{{1.,2.},{ 2.,3.}};


Thanks,


Clint Zeringue

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