Re: Counting list elements above/below a given value
- To: mathgroup at smc.vnet.net
- Subject: [mg17295] Re: Counting list elements above/below a given value
- From: tobiasoed at my-dejanews.com
- Date: Fri, 30 Apr 1999 23:22:27 -0400
- Organization: Deja News - The Leader in Internet Discussion
- Sender: owner-wri-mathgroup at wolfram.com
These are my ideas but they don't beat yours...
In[38]:= e=Table[Random[],{i,10000}];
In[39]:= value=.5
Out[39]= 0.5
In[40]:= Timing[Length[Select[Flatten[e], value > #1&]]]
Out[40]= {1.53 Second, 4999}
In[41]:= Timing[ii=0;Scan[If[value>#,ii++]&,e];ii]
Out[41]= {3.08 Second, 4999}
In[42]:= Timing[Count[e,x_ /; value>x]]
Out[42]= {2.14 Second, 4999}
In[43]:= Timing[Count[e,_?((value>#)&)]]
Out[43]= {2.06 Second, 4999}
In[44]:= Timing[Apply[Plus,Map[If[value>#,1,0]&,e]]]
Out[44]= {2.28 Second, 4999}
Tobias
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