WEKA Nodes (still) ignore their settings...

WEKA Nodes, like IBk, completely ignore their settings. See the attacheched sample - upper IBks should use 1 NN, while lower ones - 5 NN. The WEKA 3.6 works ok, but 3.7 always act as 1 NN.

While restoring the worklow it returns an error:

"ERROR     WekaSerializer                     Unexpected error while loading settings from class: weka.classifiers.lazy.IBk, using default values"

Dear torczyk

which KNIME version are you using. We fixed some minor weka bug with our latest 2.11.2 release. Could you check if this resolves your probleme?

Cheers, Iris

I'm using KNIME 2.11.2 and WEKA 3.7 doesn't work properly since the introduction of flow variables to it. I've also tried a fresh install on a different machine and the issue is fully repeatable.

Any news? Were you able to reproduce the issue?


I was able to reproduce it. This seems to be a Weka internal problem, from what I see. The loading of the settings fails, because they contain no value for the option -A, which is the distanceFunction to use. In the code of the IBk node in the function listOptions() we find:

    newVector.addElement(new Option(
	      "\tThe nearest neighbour search algorithm to use "+
          "(default: weka.core.neighboursearch.LinearNNSearch).\n",
	      "A", 0, "-A"));

The 0 is the number of arguments for this option, which is definitely wrong.

// Edit: This might not be wrong, because there is a default value that can be set. I will look into it.



Alexander has found the cause of the problem. It will be fixed in KNIME 2.11.3.

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Nice to hear that. Hope it will finally work as expected.