Author scoder
Recipients alex, ezio.melotti, scoder, steven.daprano, terry.reedy, thomasahle, tim.peters, vajrasky
Date 2014-06-01.07:27:53
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Message-id <1401607674.94.0.247718876699.issue21592@psf.upfronthosting.co.za>
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I tried the same with a Cython compiled version of select.py in the latest CPython 3.5 build. It pretty clearly shows that select2 is pretty much always faster than sorting, by a factor of 2-5x or so. I'll also attach the annotated source file that Cython generates.

*** CPython 3.5 (de01f7c37b53)

== Single call mode ==
N        sort     select7  select23 select47 select97 select   select2
-------- -------- -------- -------- -------- -------- -------- --------
    5000    0.000    0.001    0.001    0.001    0.001    0.001    0.001
   10000    0.001    0.003    0.002    0.002    0.002    0.003    0.002
   50000    0.005    0.015    0.010    0.010    0.010    0.013    0.008
  100000    0.012    0.032    0.023    0.023    0.023    0.027    0.017
  500000    0.085    0.174    0.131    0.129    0.155    0.167    0.103
 1000000    0.190    0.375    0.300    0.272    0.311    0.456    0.292
 2000000    0.422    0.828    0.588    0.579    0.689    0.865    0.560
 3000000    0.680    1.187    0.918    0.906    0.915    1.427    0.801
 4000000    0.948    1.574    1.180    1.146    1.177    1.659    1.004
 5000000    1.253    2.027    1.684    1.523    1.598    1.874    1.085
 6000000    1.577    2.441    1.892    1.754    1.787    2.659    1.055
 7000000    1.934    2.870    2.128    2.062    2.093    3.289    1.274
 8000000    2.279    3.304    2.430    2.421    2.471    2.569    2.449
 9000000    2.560    3.767    2.835    2.768    2.771    3.089    2.348
10000000    2.790    4.123    3.153    3.044    3.097    4.366    3.764
11000000    3.199    4.605    3.658    3.467    3.383    3.867    4.599
Total elapsed time: 9.13 minutes


*** Cython / CPython 3.5

== Single call mode ==
N        sort     select7  select23 select47 select97 select   select2
-------- -------- -------- -------- -------- -------- -------- --------
    5000    0.000    0.001    0.000    0.000    0.001    0.000    0.000
   10000    0.001    0.001    0.001    0.001    0.001    0.000    0.000
   50000    0.006    0.006    0.005    0.005    0.006    0.001    0.001
  100000    0.013    0.014    0.011    0.012    0.013    0.004    0.004
  500000    0.089    0.091    0.073    0.075    0.079    0.048    0.049
 1000000    0.200    0.192    0.156    0.158    0.194    0.081    0.073
 2000000    0.451    0.417    0.324    0.355    0.404    0.210    0.135
 3000000    0.678    0.614    0.496    0.501    0.530    0.291    0.277
 4000000    0.980    0.835    0.720    0.680    0.718    0.402    0.441
 5000000    1.276    1.197    0.846    0.857    0.905    0.491    0.425
 6000000    1.535    1.274    1.067    1.040    1.087    0.534    0.451
 7000000    1.842    1.500    1.226    1.214    1.279    0.549    0.507
 8000000    2.168    1.726    1.384    1.398    1.491    0.557    0.535
 9000000    2.438    1.987    1.566    1.582    1.660    0.966    0.544
10000000    2.768    2.187    1.747    1.773    1.911    1.116    0.640
11000000    3.116    2.417    1.922    1.950    2.063    1.283    1.024
Total elapsed time: 5.48 minutes
History
Date User Action Args
2014-06-01 07:27:55scodersetrecipients: + scoder, tim.peters, terry.reedy, ezio.melotti, steven.daprano, alex, thomasahle, vajrasky
2014-06-01 07:27:54scodersetmessageid: <1401607674.94.0.247718876699.issue21592@psf.upfronthosting.co.za>
2014-06-01 07:27:54scoderlinkissue21592 messages
2014-06-01 07:27:53scodercreate