[scikit-learn] Fwd: inconsistency between libsvm and scikit-learn.svc results

[elgesto at gmail.com]

I have a project that is based on SVM algorithm implemented by libsvm
<https://www.csie.ntu.edu.tw/~cjlin/libsvm/>. Recently I decided to try
several other classification algorithm, this is where scikit-learn
<http://scikit-learn.org/> comes to the picture.

The connection to the scikit was pretty straightforward, it supports libsvm
format by load_svmlight_file routine. Ans it's svm implementation is based
on the same libsvm.

When everything was done, I decided to the check the consistence of the
results by directly running libsvm and via scikit-learn, and the results
were different. Among 18 measures in learning curves, 7 were different, and
the difference is located at the small steps of the learning curve. The
libsvm results seems much more stable, but scikit-learn results have some
drastic fluctuation.

The classifiers have exactly the same parameters of course. I tried to
check the version of libsvm in scikit-learn implementation, but I din't
find it, the only thing I found was libsvm.so file.

Currently I am using libsvm 3.21 version, and scikit-learn 0.17.1 version.

I wound appreciate any help in addressing this issue.


size    libsvm                  scikit-learn
1       0.1336239435355727      0.1336239435355727
2       0.08699516468193455     0.08699516468193455
3       0.32928301642777424     0.2117238289550198      #different
4       0.2835688734876902      0.2835688734876902
5       0.27846766962743097     0.26651875338163966     #different
6       0.2853854654662907      0.18898048915599963     #different
7       0.28196058132165136     0.28196058132165136
8       0.31473956032575623     0.1958710201604552      #different
9       0.33588303670653136     0.2101641630182972      #different
10      0.4075242509025311      0.2997807499800962      #different
15      0.4391771087975972      0.4391771087975972
20      0.3837789445609818      0.2713167833345173      #different
25      0.4252154334940311      0.4252154334940311
30      0.4256407777477492      0.4256407777477492
35      0.45314944605858387     0.45314944605858387
40      0.4278633233755064      0.4278633233755064
45      0.46174762022239796     0.46174762022239796
50      0.45370452524846866     0.45370452524846866
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